Unit tests w/dynamic content to "dynamic-presubmit"

put unit tests that need dynamic content into a "dynamic-presubmit"
grouping so that we can run them with proper flags.

Bug: 167284748
Test: atest --include-subdir frameworks/av/media:dynamic-presubmit \
       -- --enable-module-dynamic-download=true
Change-Id: I39f9373ab1f543dacfae6b420a6969e1603b25dd
diff --git a/media/extractors/TEST_MAPPING b/media/extractors/TEST_MAPPING
index 038b99a..4984b8f 100644
--- a/media/extractors/TEST_MAPPING
+++ b/media/extractors/TEST_MAPPING
@@ -1,7 +1,5 @@
 {
   "presubmit": [
-    // TODO(b/148094059): unit tests not allowed to download content
-    // { "name": "ExtractorUnitTest" },
 
     // TODO(b/153661591) enable test once the bug is fixed
     // This tests the extractor path
@@ -16,5 +14,14 @@
     //      }
     //    ]
     //  }
+  ],
+
+  // 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": "ExtractorUnitTest" }
   ]
+
+
 }