java_sdk_library: Require xml permission file only if it is generated

Eliminates invalid LOCAL_REQUIRED_MODULES lines in the generated
Android.mk entries.

Bug: 7456955
Test: TH artifact noop
Test: Add unittest to java/androidmk_test.go
Test: m nothing and verify build rule doesn't contain invalid REQUIRED
Change-Id: Ic8d7e6d08181f6a24fd2aa86479bb9303cfd9be8
diff --git a/java/sdk_library.go b/java/sdk_library.go
index 503ad59..071ae11 100644
--- a/java/sdk_library.go
+++ b/java/sdk_library.go
@@ -1042,8 +1042,10 @@
 		return nil
 	}
 	entriesList := module.Library.AndroidMkEntries()
-	entries := &entriesList[0]
-	entries.Required = append(entries.Required, module.xmlPermissionsModuleName())
+	if module.sharedLibrary() {
+		entries := &entriesList[0]
+		entries.Required = append(entries.Required, module.xmlPermissionsModuleName())
+	}
 	return entriesList
 }