[android] show less obstrusive remove button for pending contacts

This uses the same button as the RSS feed items

briar-android/src/main/java/org/briarproject/briar/android/contact/add/remote/PendingContactViewHolder.java

 package org.briarproject.briar.android.contact.add.remote;
 
 import android.support.v4.content.ContextCompat;
+import android.support.v7.widget.AppCompatImageButton;
 import android.support.v7.widget.RecyclerView.ViewHolder;
 import android.view.View;
-import android.widget.Button;
 import android.widget.TextView;
 
 import org.briarproject.bramble.api.contact.PendingContact;
@@ -21,7 +21,7 @@ class PendingContactViewHolder extends ViewHolder {
 	private final TextView name;
 	private final TextView time;
 	private final TextView status;
-	private final Button removeButton;
+	private final AppCompatImageButton removeButton;
 
 	PendingContactViewHolder(View v, PendingContactListener listener) {
 		super(v);

briar-android/src/main/res/layout/list_item_pending_contact.xml

@@ -22,33 +22,43 @@
 		android:id="@+id/name"
 		android:layout_width="wrap_content"
 		android:layout_height="wrap_content"
-		android:layout_marginEnd="@dimen/margin_large"
 		android:layout_marginLeft="@dimen/margin_large"
-		android:layout_marginRight="@dimen/margin_large"
 		android:layout_marginStart="@dimen/margin_large"
 		android:layout_marginTop="@dimen/margin_large"
 		android:textColor="?android:attr/textColorPrimary"
 		android:textSize="@dimen/text_size_medium"
 		app:layout_constrainedWidth="true"
 		app:layout_constraintBottom_toTopOf="@+id/status"
-		app:layout_constraintEnd_toStartOf="@+id/time"
-		app:layout_constraintHorizontal_bias="0.5"
+		app:layout_constraintEnd_toStartOf="@+id/removeButton"
 		app:layout_constraintHorizontal_chainStyle="spread_inside"
 		app:layout_constraintStart_toEndOf="@+id/avatar"
 		app:layout_constraintTop_toTopOf="parent"
 		app:layout_constraintVertical_chainStyle="packed"
 		tools:text="This is a name of a contact"/>
 
+	<android.support.v7.widget.AppCompatImageButton
+		android:id="@+id/removeButton"
+		android:layout_width="@dimen/button_size"
+		android:layout_height="@dimen/button_size"
+		android:background="?attr/selectableItemBackgroundBorderless"
+		android:contentDescription="@string/groups_remove"
+		android:src="@drawable/action_delete_black"
+		app:layout_constraintEnd_toEndOf="parent"
+		app:layout_constraintStart_toEndOf="@+id/name"
+		app:layout_constraintTop_toTopOf="parent"
+		app:tint="?attr/colorControlNormal"/>
+
 	<TextView
 		android:id="@+id/status"
-		android:layout_width="wrap_content"
+		android:layout_width="0dp"
 		android:layout_height="wrap_content"
-		android:layout_marginBottom="16dp"
+		android:layout_marginEnd="16dp"
+		android:layout_marginRight="16dp"
 		android:layout_marginTop="8dp"
 		android:text="@string/adding_contact_failed"
 		app:layout_constrainedWidth="true"
-		app:layout_constraintEnd_toStartOf="@+id/removeButton"
-		app:layout_constraintHorizontal_bias="0.0"
+		app:layout_constraintBottom_toTopOf="@+id/divider"
+		app:layout_constraintEnd_toStartOf="@+id/time"
 		app:layout_constraintStart_toStartOf="@+id/name"
 		app:layout_constraintTop_toBottomOf="@+id/name"
 		tools:textColor="@color/briar_red"/>
@@ -57,35 +67,27 @@
 		android:id="@+id/time"
 		android:layout_width="wrap_content"
 		android:layout_height="wrap_content"
-		android:layout_margin="@dimen/margin_large"
+		android:layout_marginEnd="@dimen/margin_large"
+		android:layout_marginRight="@dimen/margin_large"
+		android:layout_marginTop="0dp"
 		android:textColor="?android:attr/textColorSecondary"
 		android:textSize="@dimen/text_size_small"
-		app:layout_constraintBottom_toBottomOf="@+id/status"
+		app:layout_constraintBottom_toTopOf="@+id/divider"
 		app:layout_constraintEnd_toEndOf="parent"
-		app:layout_constraintStart_toEndOf="@+id/name"
-		app:layout_constraintTop_toTopOf="@+id/name"
+		app:layout_constraintStart_toEndOf="@+id/status"
+		app:layout_constraintTop_toTopOf="@+id/status"
+		app:layout_constraintVertical_bias="0.0"
 		tools:text="Dec 24"/>
 
-	<Button
-		android:id="@+id/removeButton"
-		style="@style/BriarButtonFlat.Negative"
-		android:layout_width="wrap_content"
-		android:layout_height="wrap_content"
-		android:text="@string/groups_remove"
-		app:layout_constraintEnd_toEndOf="@+id/time"
-		app:layout_constraintHorizontal_bias="1.0"
-		app:layout_constraintStart_toStartOf="parent"
-		app:layout_constraintTop_toBottomOf="@+id/time"/>
-
 	<View
 		android:id="@+id/divider"
 		style="@style/Divider.ContactList"
 		android:layout_width="0dp"
 		android:layout_marginLeft="8dp"
 		android:layout_marginStart="8dp"
+		android:layout_marginTop="@dimen/margin_large"
 		app:layout_constraintEnd_toEndOf="parent"
 		app:layout_constraintStart_toEndOf="@+id/avatar"
-		app:layout_constraintTop_toBottomOf="@+id/removeButton"
-		app:layout_goneMarginTop="@dimen/margin_large"/>
+		app:layout_constraintTop_toBottomOf="@+id/status"/>
 
 </android.support.constraint.ConstraintLayout>