MediaDrmTest: cover MediaDrm$PlaybackComponent#getLogSessionId

Bug: 184396556
Test: atest MediaDrmTest
Change-Id: I61798c6115706e028cb07bcae7f77f3be13b1e50
diff --git a/tests/tests/mediadrm/src/android/mediadrm/cts/MediaDrmTest.java b/tests/tests/mediadrm/src/android/mediadrm/cts/MediaDrmTest.java
index 342ef90..31d4dd5 100644
--- a/tests/tests/mediadrm/src/android/mediadrm/cts/MediaDrmTest.java
+++ b/tests/tests/mediadrm/src/android/mediadrm/cts/MediaDrmTest.java
@@ -133,8 +133,10 @@
 
                 String logSessionId = "testPlaybackComponent";
                 component.setLogSessionId(new LogSessionId(logSessionId));
+                assertEquals(logSessionId, component.getLogSessionId().getStringId(),
+                        "LogSessionId not set");
                 PersistableBundle metrics = drm.getMetrics();
-                assertTrue("LogSessionId not set",
+                assertTrue("LogSessionId not found in metrics",
                         searchMetricsForValue(metrics, logSessionId));
             } catch (UnsupportedOperationException | NotProvisionedException e) {
                 Log.w(TAG, "testPlaybackComponent: skipping scheme " + scheme, e);