Have vold inform keymaster that early boot ended

Just before mounting partition(s) not verified by verified boot, vold
should notify keymaster that early boot has ended so it won't allow
EARLY_BOOT_ONLY keys to be created or used.

Test: VtsHalKeymasterV4_1TargetTest
Change-Id: I74ffec8d5b33f01e62f845a8fc824b3a3cad50f3
Merged-In: I74ffec8d5b33f01e62f845a8fc824b3a3cad50f3