Removing reflection access ProgressBar#mDuration

For the following reasons:
1. Developers can set this via XML
2. Using this value is inferior to setting an
indeterminate drawable that implements Animatable.

Fixes: 124052713
Test: No new implementation, so no tests.

Change-Id: Ie1e23f75328cce5d8f4d317625d8f38c0a166352
2 files changed