Set min_sdk_version to be part of mainline modules

Modules contributing mainline modules (APK/APEX) should set
min_sdk_version as well as apex_available.

For now setting min_sdk_version doesn't change build outputs.
But build-time checks will be added soon.

This is one of two parts: covers mainline-related files.

Bug: 152655956
Test: m
Change-Id: I558b2d717d6cbae920db008d1b0f3ed61958937b
diff --git a/media/extractors/Android.bp b/media/extractors/Android.bp
index bb42580..7c4e62f 100644
--- a/media/extractors/Android.bp
+++ b/media/extractors/Android.bp
@@ -24,6 +24,9 @@
         "libmediandk#29",
     ],
 
+    // extractors are supposed to work on Q(29)
+    min_sdk_version: "29",
+
     relative_install_path: "extractors",
 
     compile_multilib: "first",