Migrate PiP2 flag to aconfig

Bug: 304838465
Test: m -j
Flag: ACONFIG com.android.wm.shell.enable_pip2_implementation DEVELOPMENT
Change-Id: I84dd3740915869ff913919b926110b4ae14dcb12
diff --git a/libs/WindowManager/Shell/aconfig/multitasking.aconfig b/libs/WindowManager/Shell/aconfig/multitasking.aconfig
index c366ccd..4d2d960 100644
--- a/libs/WindowManager/Shell/aconfig/multitasking.aconfig
+++ b/libs/WindowManager/Shell/aconfig/multitasking.aconfig
@@ -42,3 +42,11 @@
     description: "Enables PiP UI state callback on entering"
     bug: "303718131"
 }
+
+flag {
+    name: "enable_pip2_implementation"
+    namespace: "multitasking"
+    description: "Enables the new implementation of PiP (PiP2)"
+    bug: "290220798"
+    is_fixed_read_only: true
+}
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/common/pip/PipUtils.kt b/libs/WindowManager/Shell/src/com/android/wm/shell/common/pip/PipUtils.kt
index 108aa82..1e30d8f 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/common/pip/PipUtils.kt
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/common/pip/PipUtils.kt
@@ -21,13 +21,13 @@
 import android.content.ComponentName
 import android.content.Context
 import android.os.RemoteException
-import android.os.SystemProperties
 import android.util.DisplayMetrics
 import android.util.Log
 import android.util.Pair
 import android.util.TypedValue
 import android.window.TaskSnapshot
 import com.android.internal.protolog.common.ProtoLog
+import com.android.wm.shell.Flags
 import com.android.wm.shell.protolog.ShellProtoLogGroup
 import kotlin.math.abs
 
@@ -37,7 +37,6 @@
 
     // Minimum difference between two floats (e.g. aspect ratios) to consider them not equal.
     private const val EPSILON = 1e-7
-    private const val ENABLE_PIP2_IMPLEMENTATION = "persist.wm.debug.enable_pip2_implementation"
 
     /**
      * @return the ComponentName and user id of the top non-SystemUI activity in the pinned stack.
@@ -138,5 +137,5 @@
 
     @JvmStatic
     val isPip2ExperimentEnabled: Boolean
-        get() = SystemProperties.getBoolean(ENABLE_PIP2_IMPLEMENTATION, false)
+        get() = Flags.enablePip2Implementation()
 }
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