Add some NullPointerExceptions to AndroidKeyStore

Existing KeyStore implementations throw NullPointerExceptions beacuse
the KeyStoreSpi doesn't check these arguments for null. Add in checks so
we don't accidentally check some bogus values.

Also switch a RuntimeException to a KeyStoreException

Change-Id: I18f4d4474d607cb2057ea8069b901e0992275e78
1 file changed