Migrate screenshot methods to AIDL

Additonal service, named as "SurfaceFlingerAIDL", is added to surfaceflinger during the process of migrating ISurfaceComposer interface to AIDL. New changes are put into namespace, android::gui. Once migration is complete, this service will be deleted.

This CL migrates Screenshot methods to AIDL, more will come.

Bug: 211037638
Test: screencap
Merged-In: Idee91fa2444646639735847b1c76e983af39227f
Change-Id: Idee91fa2444646639735847b1c76e983af39227f
diff --git a/services/surfaceflinger/Android.bp b/services/surfaceflinger/Android.bp
index d9958f3..000a2cb 100644
--- a/services/surfaceflinger/Android.bp
+++ b/services/surfaceflinger/Android.bp
@@ -76,6 +76,7 @@
         "libaidlcommonsupport",
         "libcompositionengine",
         "libframetimeline",
+        "libgui_aidl_static",
         "libperfetto_client_experimental",
         "librenderengine",
         "libscheduler",