Disable seamless-rotation when other windows are visible.

Was never supported but has gotten more horrific for whatever reason.

Bug: 65612427
Change-Id: I25758f40876c76a6daaf6330ed7cfa84c759fc0f
diff --git a/services/core/java/com/android/server/wm/Session.java b/services/core/java/com/android/server/wm/Session.java
index 1781247..4dd147e 100644
--- a/services/core/java/com/android/server/wm/Session.java
+++ b/services/core/java/com/android/server/wm/Session.java
@@ -719,4 +719,8 @@
     public String toString() {
         return mStringName;
     }
+
+    boolean hasAlertWindowSurfaces() {
+        return !mAlertWindowSurfaces.isEmpty();
+    }
 }