stagefright: enable adaptive playback based on codec format key

Added support for prepareForAdaptivePlayback() call in
configureCodec, if max-width and max-height keys are specified
in the format.  It is OK for this call to fail, if component
does not implement adaptive playback.

Change-Id: Ie15892bc666df103b635890a0fda799b204bb06c
Signed-off-by: Lajos Molnar <lajos@google.com>
Bug: 7093648
Bug: 10192531