Move java.sdkSpec to the android package

... in preparation for making the handling of sdk versions consistent
across java and cc modules.

Bug: 175678607
Test: m
Change-Id: I598f0454bce9b7320621022115412fbe97403945
diff --git a/sysprop/sysprop_test.go b/sysprop/sysprop_test.go
index e9d9051..f42f9e9 100644
--- a/sysprop/sysprop_test.go
+++ b/sysprop/sysprop_test.go
@@ -371,6 +371,6 @@
 	android.AssertStringEquals(t, "min_sdk_version forwarding to cc module", "29", propFromCc)
 
 	javaModule := result.ModuleForTests("sysprop-platform", "android_common").Module().(*java.Library)
-	propFromJava := javaModule.MinSdkVersion()
+	propFromJava := javaModule.MinSdkVersionString()
 	android.AssertStringEquals(t, "min_sdk_version forwarding to java module", "30", propFromJava)
 }