ANR when copying and pasting long strings of emoji

Copying and pasting long strings of emoji from EmojiTextView to EmojiEditText is very slow and can produce an ANR dialog. The delay increases superlinearly with the number of emoji, and depends on the existing contents of the EmojiEditText.

With the Huawei Ascend Y330:

• 64 emoji: noticeable delay
• 128 emoji: 6 seconds if EmojiEditText is empty, 20 seconds if it already contains 128 emoji
• 256 emoji: 30 seconds if EmojiEditText is empty, 100 seconds if it already contains 256 emoji

With the Samsung Galaxy Ace 2:

• 128 emoji: noticeable delay
• 256 emoji: 6 seconds if EmojiEditText is empty, 18 seconds if it already contains 256 emoji
• 512 emoji: 37 seconds if EmojiEditText is empty, 135 seconds if it already contains 512 emoji

These problems don't occur when copying and pasting ordinary text from an EmojiTextView to an EmojiEditText. Thousands of characters can be copied and pasted without a noticeable delay.