power-libperfmgr: Add a timer mechanism to load signal boost

Currently, load hint signals boost the first frame but rely on frames
reporting an actual duration to end that boost. This change adds a
secondary timer to provide a maximum boost time based on the target,
in case the session fails to report an actual duration or gets rate
limited.

This patch also refactors the existing timer into a generic superclass
to make sharing timer logic easier.

Bug: 261130508
Test: manual
Change-Id: Icc7fbaed0cb764b6960a8f92a2b6505c7a8583dc
2 files changed