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: Ida890adfe6dfac79267fc0e18b63d2330266438c

libsystem/Android.bp

@@ -8,6 +8,7 @@ cc_library_headers {
         "//apex_available:platform",
         "//apex_available:anyapex",
     ],
+    min_sdk_version: "apex_inherit",
     export_include_dirs: ["include"],
 
     target: {

libsysutils/Android.bp

@@ -43,6 +43,7 @@ cc_library {
         "//apex_available:anyapex",
         "//apex_available:platform",
     ],
+    min_sdk_version: "apex_inherit",
 }
 
 cc_test {

libutils/Android.bp

@@ -22,6 +22,7 @@ cc_library_headers {
         "//apex_available:platform",
         "//apex_available:anyapex",
     ],
+    min_sdk_version: "apex_inherit",
 
     header_libs: [
         "liblog_headers",
@@ -162,6 +163,7 @@ cc_library {
         "//apex_available:anyapex",
         "//apex_available:platform",
     ],
+    min_sdk_version: "apex_inherit",
 }
 
 cc_library {