manifest_fixer argument should be --use-embedded-dex rather than --use-embedded-dex=true

Test: building soong tests, treehugger
Change-Id: Id0df92171a2e547794979fb473d8abc47f33d13c
diff --git a/java/android_manifest.go b/java/android_manifest.go
index 7b378cd..5d3cfa5 100644
--- a/java/android_manifest.go
+++ b/java/android_manifest.go
@@ -66,7 +66,7 @@
 	}
 
 	if useEmbeddedDex {
-		args = append(args, "--use-embedded-dex=true")
+		args = append(args, "--use-embedded-dex")
 	}
 
 	var deps android.Paths