PowerManager: Adds isSustainedPerformanceModeSupported()

isSustainedPerformanceModeSupported() returns true if the device
supports the mode. It checks for the boolean config
"config_sustainedPerformanceModeSupported" to be set.

Bug: 22864186
Change-Id: I0f9f0bcbb8c02b19f37e9c87570d88e8f78f7992
Signed-off-by: Ruchi Kandoi <kandoiruchi@google.com>
6 files changed