Use CLOCK_BOOTTIME for keystore2 auth token received time

CLOCK_BOOTTIME is more correct because it includes time spent
while the device is suspended.

This also fixes an issue when comparing the times resulting from the
get_last_auth_time() API in the Java world, because we want to use
SystemClock.elapsedRealtime(), which uses CLOCK_BOOTTIME.

Bug: 309686873
Test: atest keystore2_client_tests
Change-Id: I89d71ccfcfe4f8b3495fede40ae26ad6fa2b0118
1 file changed