Fix CharBuffer.subSequence return type.

Bug: 3484927
Change-Id: I06dae03b0803d1373e268e854e9e0e4b6c59e13a
Fix URLConnectionTest after latest okhttp update.

I've observed 14 failing tests both before and after
the update.

Change-Id: I40dfd9efe35ed03d89b38b030d3c7b6558b247e2
Merge "Fix URLConnectionTest after latest okhttp update."
Merge "Fix CharBuffer.subSequence return type."
Merge https://android.googlesource.com/platform/libcore into jb-devel