Update manifest shortcut XML schema

Use the standard <intent> tag instead of custom tags.

- Also fix setDynamicShortcuts(), which was broken in the previous CL.
- Also tolerate runtime exceptions while parsing XMLs
- Also fix b/29422018 while I'm at it

Bug 29390156
Bug 29077932
Bug 29422018

Change-Id: I2756c9d66c6d7b2962a982d9e57a7d84a5755b28
24 files changed