Move codec code out of omx plugin directories

separate actual codec code for amrnb, amrwb, m4v_h263, and mp3dec from
the OMX plugins.

Bug: 147679485
Test: build
Change-Id: I8b6005384872e667cdcf5f700a848beba355a395
diff --git a/media/codecs/amrnb/TEST_MAPPING b/media/codecs/amrnb/TEST_MAPPING
new file mode 100644
index 0000000..343d08a
--- /dev/null
+++ b/media/codecs/amrnb/TEST_MAPPING
@@ -0,0 +1,10 @@
+// mappings for frameworks/av/media/libstagefright/codecs/amrnb
+{
+  // tests which require dynamic content
+  // invoke with: atest -- --enable-module-dynamic-download=true
+  // TODO(b/148094059): unit tests not allowed to download content
+  "dynamic-presubmit": [
+    { "name": "AmrnbDecoderTest"},
+    { "name": "AmrnbEncoderTest"}
+  ]
+}