Keystore 2.0 SPI: Fix installation of legacy Keystore provider

Priviously we installed the legacy keystore SPI by the name
KeyStore.AndroidKeyStore and set an alias to
KeyStore.AndroidKeyStoreLegacy. This conflicted with with the Keystore
provider which also registers as KeyStore.AndroidKeyStore.
This patch registers the old provider only by the name
KeyStore.AndroidKeyStore.

Test: CtsLibcoreTestCases:libcore.java.security.ProviderTest#test_Provider_Properties
      Also, the device boots.
Change-Id: I38a248a996839f397bdcae30fd1b03a883209df2