Tune GPU dvfs period during app launch

Instead of using hard-coded GPU freq, tune
DVFS period instead.

Test: Boot
Bug: 239887528
Signed-off-by: Wei Wang <wvw@google.com>
Change-Id: I53415fb5c5390adace99b593495c6388b3232cd0
(cherry picked from commit 801a6700)
Merged-In: I53415fb5c5390adace99b593495c6388b3232cd0