Dotcase: Improve exception-handling

Don't catch generic Exception, and log exceptions as errors. Also,
remove try-catch blocks around things which seemingly do not throw any
exception.

Change-Id: I333be1f178fec12f38caded0c176c93f6ed710b1
(cherry picked from commit 700e26de9429a6ce6d080a817e4240cf42c36102)
Dotcase: Only check for new notifications before displaying them

Rather than check for new notifications on every redraw, only check at
the beginning of each animation cycle (i.e., right before they're
about to be shown). This reduces notification checks from about twice
per second to about every 3 seconds.

Change-Id: Ia53de5bc24f3e41d33bfe5bc7c0f56b284e4d3e8
(cherry picked from commit 96e6ee2518fc70f30656e2498d4d5d91d8a33dbf)
Dotcase: Add another missed exception

Change-Id: I510100de4fc71af24060fc3e6ddf19c47520b7a7
(cherry picked from commit a67cde2e4e411bd07a1ca2821e4193608bb0e0d4)
media_codecs: Remove mpeg4/h263/h264 ffmpeg entries

Change-Id: I60bc2be88ae3a7be5d5c86ad901ccc41de079929
(cherry picked from commit 6dcb10e3141693794a6506d665528c75732e223d)