Improve Android change markers

This change documents most existing local patches.

The remaining changes are:
1) An extra line in replaceWith() which will be removed
in a follow up change.
2) Bug 73550237 covers the changes in canEncode() and
will be resolved in a follow-up change.

Bug: 69710405
Test: make droid
Change-Id: I9af57e3ed267750d788f2ca59e3dcf182de69346
1 file changed