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/java/app_import.go b/java/app_import.go
index d4da64d..32cec23 100644
--- a/java/app_import.go
+++ b/java/app_import.go
@@ -394,12 +394,12 @@
 	return false
 }
 
-func (a *AndroidAppImport) sdkVersion() sdkSpec {
-	return sdkSpecFrom("")
+func (a *AndroidAppImport) SdkVersion() android.SdkSpec {
+	return android.SdkSpecFrom("")
 }
 
-func (a *AndroidAppImport) minSdkVersion() sdkSpec {
-	return sdkSpecFrom("")
+func (a *AndroidAppImport) MinSdkVersion() android.SdkSpec {
+	return android.SdkSpecFrom("")
 }
 
 var _ android.ApexModule = (*AndroidAppImport)(nil)