Rename ByteBufferAs*.offset to byteOffset

The super class, e.g. CharBuffer, has a field "offset" and it
has a different meaning. Renaming the field to avoid confusing.

Also, annotate methods in @Override to enforce the compiler check,
even though it's a Android patch.

No functional change is expected.

Bug: 269740550
Test: m droid
Change-Id: I8cde1dc8fc97bf08090e9831510c7449e715c182
7 files changed