Add aconfig: enable_pip_umo_experience

This CL adds a new flag into multitask.aconfig, when it's enabled, we
switch to use the new UMO experience for PiP menu if applicable (like
for video playback apps).

Bug: 307998712
Flag: enable_pip_umo_experience
Test: N/A
Change-Id: Ic73b3924753efb48dba71af698c481f140a9f142
diff --git a/libs/WindowManager/Shell/aconfig/multitasking.aconfig b/libs/WindowManager/Shell/aconfig/multitasking.aconfig
index 1cc8a8f..2b95f30 100644
--- a/libs/WindowManager/Shell/aconfig/multitasking.aconfig
+++ b/libs/WindowManager/Shell/aconfig/multitasking.aconfig
@@ -50,3 +50,10 @@
     description: "Enables new animations for expand and collapse for bubbles"
     bug: "311450609"
 }
+
+flag {
+    name: "enable_pip_umo_experience"
+    namespace: "multitasking"
+    description: "Enables new UMO experience for PiP menu"
+    bug: "307998712"
+}