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.

Bug: 152655956
Test: m
Change-Id: Id89bcc591effc436a7c4a22f4320331d187d2ee7

Android.bp

diff --git a/Android.bp b/Android.bp
index bf31f27..290835f 100644
--- a/Android.bp
+++ b/Android.bp
@@ -22,6 +22,13 @@
         enabled: true,
     },
     double_loadable: true,
+    apex_available: [
+        "//apex_available:platform",
+        "com.android.media",
+        "com.android.media.swcodec",
+    ],
+    min_sdk_version: "29",
+
     arch: {
         arm: {
             instruction_set: "arm",