SystemUI include static lib WindowManager-Shell(1/N)

Test: make SystemUI
Test: $OUT_TARGET/common/obj/APPS/SystemUI_intermediates/classes.jar \
      include /com/android/wm/shell/WindowManagerShell.class
Test: $OUT/system_ext/priv-app/SystemUI/SystemUI.apk \
      decompile classes.dex to find WindowManagerShell.class
Test: atest SystemUITests

Bug: 161118569
Change-Id: I886222562458b8b1f5a2ec36dc5345073d08221c

packages/SystemUI/Android.bp

@@ -140,7 +140,8 @@ android_library {
         "testables",
         "truth-prebuilt",
         "dagger2",
-        "jsr330"
+        "jsr330",
+        "WindowManager-Shell",
     ],
     libs: [
         "android.test.runner",

packages/SystemUI/proguard.flags

@@ -39,4 +39,6 @@
 
 -keep public class * extends com.android.systemui.SystemUI {
     public <init>(android.content.Context);
-}
+}
+
+-keep class com.android.wm.shell.*