Fix trivial warnings hidden by -isystem

Fix the trivial warnings that are hidden by the use of -isystem to
include frameworks/av and caught by -Werror.

Test: m -j checkbuild
Bug: 31751828
Change-Id: I155f9f772ce0a84b364313814cb7cf528b9de4eb
diff --git a/media/libmediaplayerservice/include/MediaPlayerInterface.h b/media/libmediaplayerservice/include/MediaPlayerInterface.h
index a01f7f2..e8d59a7 100644
--- a/media/libmediaplayerservice/include/MediaPlayerInterface.h
+++ b/media/libmediaplayerservice/include/MediaPlayerInterface.h
@@ -286,7 +286,7 @@
     }
 
     // Modular DRM
-    virtual status_t prepareDrm(const uint8_t uuid[16], const Vector<uint8_t>& drmSessionId) {
+    virtual status_t prepareDrm(const uint8_t /* uuid */[16], const Vector<uint8_t>& /* drmSessionId */) {
         return INVALID_OPERATION;
     }
     virtual status_t releaseDrm() {
diff --git a/media/libmediaplayerservice/nuplayer/NuPlayerRenderer.cpp b/media/libmediaplayerservice/nuplayer/NuPlayerRenderer.cpp
index 9fe61703..abda34e 100644
--- a/media/libmediaplayerservice/nuplayer/NuPlayerRenderer.cpp
+++ b/media/libmediaplayerservice/nuplayer/NuPlayerRenderer.cpp
@@ -1103,7 +1103,7 @@
             // (Case 1)
             // Must be a multiple of the frame size.  If it is not a multiple of a frame size, it
             // needs to fail, as we should not carry over fractional frames between calls.
-            CHECK_EQ(copy % mAudioSink->frameSize(), 0);
+            CHECK_EQ(copy % mAudioSink->frameSize(), 0u);
 
             // (Case 2, 3, 4)
             // Return early to the caller.
diff --git a/media/libmediaplayerservice/nuplayer/RTSPSource.cpp b/media/libmediaplayerservice/nuplayer/RTSPSource.cpp
index 9264e49..8b3d0dc 100644
--- a/media/libmediaplayerservice/nuplayer/RTSPSource.cpp
+++ b/media/libmediaplayerservice/nuplayer/RTSPSource.cpp
@@ -544,7 +544,7 @@
         return;
     }
 
-    CHECK_EQ(msg->what(), (int)kWhatNotify);
+    CHECK_EQ(msg->what(), kWhatNotify);
 
     int32_t what;
     CHECK(msg->findInt32("what", &what));