Internationalize InputFilter.AllCaps

The new code support non-BMP characters, as well as locale-specific
uppercasing and fine-grained span copying.

The modern capitalization code in AllCapsTransformationMethod is
moved to TextUtils now, so InputFilter.AllCaps can share it.

Fixes: 37222101
Test: New CTS and core tests are added.
Test: cts-tradefed run cts-dev --module CtsTextTestCases
Test: adb shell am instrument -w -e package android.text com.android.frameworks.coretests/android.support.test.runner.AndroidJUnitRunner

Change-Id: I021ff2a97a60396fb1b6e4940d91d3cd6ccb6196