Dogfood the new IR Kotlin compiler backend.

Test: make
Test: atest com.android.systemui

Change-Id: I610058001bde19554c55dee5a79ad1782abc3186

java/java.go

@@ -1446,6 +1446,9 @@ func (j *Module) compile(ctx android.ModuleContext, aaptSrcJar android.Path) {
 		kotlincFlags := j.properties.Kotlincflags
 		CheckKotlincFlags(ctx, kotlincFlags)
 
+		// Dogfood the JVM_IR backend.
+		kotlincFlags = append(kotlincFlags, "-Xuse-ir")
+
 		// If there are kotlin files, compile them first but pass all the kotlin and java files
 		// kotlinc will use the java files to resolve types referenced by the kotlin files, but
 		// won't emit any classes for them.