Add PowerManger testcases for parceable objects parceling/unparceling.

Test and veify the java to native and native to java
parceling/unparceling for:
android.os.PowerSaveState
android.os.BatterySaverPolicyConfig
android.os.WorkSource

Bug: 149479744
Test: atest PowerManagerTest
Change-Id: Idc5c4639d9a963476e7ee789be451e4db98b1735