libmediadrm: support USABLE_IN_FUTURE in getMetrics

Bug: 169073078
Test: MediaDrmMetricsTest
Test: MediaDrmTest#testValidateMetrics
Test: WidevineDashPolicyTests#testL1ValidateKeyUsableInFuture
Change-Id: I1fb5067bab63bd736b42f2034d5c2c0f1c5e3e79
1 file changed