Add min_sdk_version:R to updatable apexes

APEXes introduced in R need to set min_sdk_version to ensure that they
are built against correct version(30 or R) of stubs (libc/liblog/...).

Bug: 152655956
Test: /vendor/google/build/build_mainline_modules.sh
Change-Id: I4a893c34b09334eea124266287301e479b9e8a59
diff --git a/apex/permission/Android.bp b/apex/permission/Android.bp
index 0171b0d..71a52bb 100644
--- a/apex/permission/Android.bp
+++ b/apex/permission/Android.bp
@@ -21,6 +21,7 @@
 apex_defaults {
     name: "com.android.permission-defaults",
     updatable: true,
+    min_sdk_version: "R",
     key: "com.android.permission.key",
     certificate: ":com.android.permission.certificate",
     java_libs: [