Disable "show member in hidden parent" metalava error

There are a quite few violations unfortunately, so let's disable it for now.
The plan is to fix all the issues in the internal master and enable it.

Bug: 159121253
Test: build / Tree hugger
Change-Id: I0b0ce937ecd17853b3bb32f7605310b21be77b31
diff --git a/java/droiddoc.go b/java/droiddoc.go
index b16c9cd..3eab841 100644
--- a/java/droiddoc.go
+++ b/java/droiddoc.go
@@ -1306,6 +1306,7 @@
 			cmd.Flag("--exclude-documentation-from-stubs")
 		}
 	}
+	cmd.FlagWithArg("--hide ", "ShowingMemberInHiddenClass") // b/159121253 -- remove it once all the violations are fixed.
 }
 
 func (d *Droidstubs) annotationsFlags(ctx android.ModuleContext, cmd *android.RuleBuilderCommand) {