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: I87ce41ad18a7a39f2c6c41c5aec2d8338db3ec8d
diff --git a/Android.bp b/Android.bp
index ed29f5b..731d87b 100644
--- a/Android.bp
+++ b/Android.bp
@@ -87,6 +87,7 @@
     whole_static_libs: [
         "libhwbinder-impl-internal",
     ],
+    min_sdk_version: "29",
 }
 
 // Only libhwbinder_benchmark needs to have pgo enabled. When all places