Don't include flags in configuration change if their value hasn't changed.

This makes the check in updateFrom() match the logic in diff().

Change-Id: I3ab4e8460f7fbf985ef55b9514a8aa90d401d486
Avoid unnecessary FindClass("java/lang/String").

Use previously retrieved global reference instead.
Check for NULL after creating the global reference.

Change-Id: I21670d2ef0f63ddb5801dd21e7e56359e5519479
Fixed incorrect calculation of dirty invalidation area

Padding was already taken into consideration before calling
invalidateDrawable in ProgressBar.

Change-Id: Id7f23bd15bb19e2294c07adb2acb397100ea97e8