Revert^2 "Expose AID_KEYSTORE"

Revert submission revert-1660531-max-boot-level-crypto-KFMCEDKSIV

Reason for revert: topic:vold-use-keystore2 has landed fixing the bug

Reverted changes:
Ibf63734a: Revert "Set earlyBootEnded before apex starts"
Id02f63a7: Revert "Expose AID_KEYSTORE"
Ibcedeff4: Revert "Cryptographic security for MAX_BOOT_LEVEL"

Restored changes:
Ia3b968afc:Set earlyBootEnded before apex starts
Ia69891291:Expose AID_KEYSTORE
I12530cd13:Cryptographic security for MAX_BOOT_LEVEL

Reverted-SHA1: a801eabe

Original commit message:
Keystore uses this as the user ID for keys that it creates for its
own use.

Bug: 176450483
Test: atest com.android.tests.odsign.OnDeviceSigningHostTest#verifyArtUpgradeSignsFiles
Change-Id: I0e2baa8807281ec9e5cc0a9ff8daff191285a600