[automerger] Fix antlr gen task inputs am: 922b65c68f am: 3a28f9c1ca

Change-Id: Ic312f4917d60b3b93dfe24e890e45ed41a003171
diff --git a/room/compiler/build.gradle b/room/compiler/build.gradle
index 57ff63f..739491a 100644
--- a/room/compiler/build.gradle
+++ b/room/compiler/build.gradle
@@ -65,7 +65,7 @@
 def generateAntlrTask = task('generateAntlrGrammar', type: JavaExec) {
     def outFolder = file(antlrOut)
     outputs.dir(outFolder)
-    inputs.dir("$projectDir/SQLite.g4")
+    inputs.file("$projectDir/SQLite.g4")
     classpath configurations.runtime
     main "org.antlr.v4.Tool"
     args "SQLite.g4", "-visitor", "-o", new File(outFolder, "android/arch/persistence/room/parser").path,