misc/androidstudio: drop the clean task to fix Android Studio gradle sync

Suggestion from

https://github.com/golang/go/issues/23307#issuecomment-368162189

I've manually verified in Android Studio that removing the clean task
does fix the issue reported in golang/go#25290.

Fixes golang/go#25290.
Fixes golang/go#23307.

Change-Id: Ic1a8c240fc8e4c4aaf59977fd559dd221ff605b1
Reviewed-on: https://go-review.googlesource.com/112455
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
diff --git a/misc/androidstudio/src/main/groovy/org/golang/mobile/GobindPlugin.groovy b/misc/androidstudio/src/main/groovy/org/golang/mobile/GobindPlugin.groovy
index 6d88eeb..50ca103 100644
--- a/misc/androidstudio/src/main/groovy/org/golang/mobile/GobindPlugin.groovy
+++ b/misc/androidstudio/src/main/groovy/org/golang/mobile/GobindPlugin.groovy
@@ -65,10 +65,6 @@
 			'mylib',
 			null,
 			gomobileTask))
-
-		Task cleanTask = project.tasks.create("clean", {
-			project.delete(project.name+".aar")
-		})
 	}
 
 	private static void handleVariant(Project project, def variant) {