mt6765-common: perf: Boost foreground to maximum when launching an app

App launching is one of the tasks that can produce janks and CPU
spikes. Boosting foreground to max to open apps should improve UX.

Signed-off-by: Vaisakh Murali <mvaisakh@statixos.com>
Change-Id: I1ecd23a00d253e0ed9b2cb55c9d7b4e8bee82c89