Dump ABI for libmediametrics

It's not an LLNDK library, but has # apex APIs which need to be kept
stable.

Bug: 138219814
Test: development/vndk/tools/header-checker/utils/create_reference_dumps.py -libs libmediametrics -ref-dump-dir prebuilts/abi-dumps/platform

Change-Id: I93b494c13a46817719002e0028f4f80f0a55d512
diff --git a/media/libmediametrics/Android.bp b/media/libmediametrics/Android.bp
index 15ea578..33368be 100644
--- a/media/libmediametrics/Android.bp
+++ b/media/libmediametrics/Android.bp
@@ -37,6 +37,10 @@
             "1" ,
         ]
     },
+
+    header_abi_checker: {
+        enabled: true,
+    },
 }