Replace ApiStrToNum uses with ApiLevel.

Test: treehugger
Bug: http://b/154667674
Change-Id: I2954bb21c1cfdeb305f25cfb6c8711c930f6ed50
diff --git a/java/sdk_library.go b/java/sdk_library.go
index 1a5ef54..a7b92b3 100644
--- a/java/sdk_library.go
+++ b/java/sdk_library.go
@@ -1878,7 +1878,8 @@
 	return false
 }
 
-func (module *SdkLibraryImport) ShouldSupportSdkVersion(ctx android.BaseModuleContext, sdkVersion int) error {
+func (module *SdkLibraryImport) ShouldSupportSdkVersion(ctx android.BaseModuleContext,
+	sdkVersion android.ApiLevel) error {
 	// we don't check prebuilt modules for sdk_version
 	return nil
 }
@@ -2078,7 +2079,8 @@
 	// do nothing
 }
 
-func (module *sdkLibraryXml) ShouldSupportSdkVersion(ctx android.BaseModuleContext, sdkVersion int) error {
+func (module *sdkLibraryXml) ShouldSupportSdkVersion(ctx android.BaseModuleContext,
+	sdkVersion android.ApiLevel) error {
 	// sdkLibraryXml doesn't need to be checked separately because java_sdk_library is checked
 	return nil
 }