Enable compact entries for resource shrunken apps

For SystemUIGoogle this is a 2.3 MB reduction (17* of resources arsc) and for Traceur it is a 500k reduction (22% of resources.arsc)

Bug: 294016857
Test: Existing
Ignore-AOSP-First: The resource system support for this is not in AOSP yet

Change-Id: I513078406494ad354c255afa0e829cbe10a9b07a

java/aapt2.go

@@ -256,7 +256,8 @@ func aapt2Link(ctx android.ModuleContext,
 
 var aapt2ConvertRule = pctx.AndroidStaticRule("aapt2Convert",
 	blueprint.RuleParams{
-		Command:     `${config.Aapt2Cmd} convert --output-format $format $in -o $out`,
+		Command: `${config.Aapt2Cmd} convert --enable-compact-entries ` +
+			`--output-format $format $in -o $out`,
 		CommandDeps: []string{"${config.Aapt2Cmd}"},
 	}, "format",
 )