Ignore malformed shortcuts

After an app publishes a shortcut that contains malformed intent, the
system can be stuck in boot-loop due to uncaught exception caused by
parsing the malformed intent.

This CL ignores that particular malformed entry. Since shortcuts are
constantly writes back into the xml from system memory, the malformed
entry will be removed from the xml the next time system persists
shortcuts from memory to file system.

Bug: 246540168
Test: manual
Change-Id: I9492fcbd499ab2792c1d08884e3af394c5a4c79f