Find7: rename power HAL

Change-Id: I17bb9f6ba66e5ec3b9c3bacb5a2e2c84402d2f36
Find7: avoid collision with the aosp power HAL

Change-Id: I54fbcc6262020f6077a4f6fb1427eb164de0b939
Find7: import sepolicy from hammerhead

Change-Id: Idf2c85c75314ea8012309e569942217ed4b824c9