Keep spans while transforming to uppercase

We now use ICU's new functionality for casing edits to preserve
the spans while applying AllCapsTransformationMethod.

Test: Manual
Test: CTS tests added and pass
Bug: 7198872
Bug: 19047649
Bug: 19713814
Bug: 34853618
Bug: https://code.google.com/p/android/issues/detail?id=67509
Change-Id: I0df388e79894961efb272d497f1dcc0570a6c085