Enable atest for mediatranscoder benchmarks

Bug: 173627260
Test: push libmediatranscoder.so to /system/lib64 (if required)
Test: atest MediaTrackTranscoderBenchmark \
      -- --enable-module-dynamic-download=true
Test: atest MediaTranscoderBenchmark \
      -- --enable-module-dynamic-download=true
Test: atest MediaSampleReaderBenchmark \
      -- --enable-module-dynamic-download=true

Change-Id: I048876ecc884f534d5aeee1c173dcc4cfe838dae
diff --git a/media/libmediatranscoding/transcoder/benchmark/Android.bp b/media/libmediatranscoding/transcoder/benchmark/Android.bp
index ce34702..f77d28d 100644
--- a/media/libmediatranscoding/transcoder/benchmark/Android.bp
+++ b/media/libmediatranscoding/transcoder/benchmark/Android.bp
@@ -2,6 +2,8 @@
     name: "benchmarkdefaults",
     shared_libs: ["libmediatranscoder", "libmediandk", "libbase", "libbinder_ndk"],
     static_libs: ["libgoogle-benchmark"],
+    test_config_template: "AndroidTestTemplate.xml",
+    test_suites: ["device-tests", "TranscoderBenchmarks"],
 }
 
 cc_test {