Don't pass args to xctest cli from test listing

Summary: This is wholly un-needed since the arguments are disregarded. Let's make the command as terse as possible

Reviewed By: zeyadsalloum

Differential Revision: D25122978

fbshipit-source-id: 12995c14e9420ae01a7f74b90d62f9b1a2f54861

XCTestBootstrap/Configuration/FBXCTestConfiguration.m

@@ -311,10 +311,9 @@ - (NSString *)testType
   }
 
   NSString *xctestPath = executor.xctestPath;
-  NSArray<NSString *> *arguments = @[@"-XCTest", @"All", self.testBundlePath];
   return [FBXCTestProcess
     startWithLaunchPath:xctestPath
-    arguments:arguments
+    arguments:@[] // xctest needs no arguments as the shim will disregard & bypass them.
     environment:environment
     waitForDebugger:NO
     stdOutConsumer:stdOutConsumer