Support tailoring clang --target flag based on min sdk version.

Bug: 215748260
Test: Tested using aquery to verify the --target flag; add added unit

Change-Id: Ifb13509db7d1e110316aa44d55ec9cccaa4b83d1

cc/bp2build.go

@@ -52,6 +52,8 @@ type staticOrSharedAttributes struct {
 	System_dynamic_deps bazel.LabelListAttribute
 
 	Enabled bazel.BoolAttribute
+
+	sdkAttributes
 }
 
 // groupSrcsByExtension partitions `srcs` into groups based on file extension.
@@ -539,6 +541,18 @@ func bp2BuildParseBaseProps(ctx android.Bp2buildMutatorContext, module *Module)
 	}
 }
 
+func bp2BuildParseSdkAttributes(module *Module) sdkAttributes {
+	return sdkAttributes {
+		Sdk_version: module.Properties.Sdk_version,
+		Min_sdk_version: module.Properties.Min_sdk_version,
+	}
+}
+
+type sdkAttributes struct {
+	Sdk_version     *string
+	Min_sdk_version *string
+}
+
 // Convenience struct to hold all attributes parsed from linker properties.
 type linkerAttributes struct {
 	deps                             bazel.LabelListAttribute