FingerprintBoundKeysTest: secret key should be created before using it

The testing secret key doesn't create in onCreate(), so that
the CtsVerifier will crash when running this case. You can
check another similar case "ScreenLockBoundKeysTest.java",
it create secret key first.

Bug: 24339790
Change-Id: Ie89a4305b9f9832762c917e265c447763d816964
1 file changed