Do not set different gravity for non-moveable nav bar

Some tests assume that if the bar cannot move, it should be always
at the bottom. Otherwise the tests may fail by Gravity.RIGHT on
a default landscape display.

Bug: 267792420
Test: adb shell wm size 2200x1800
      atest DisplayPolicyInsetsTests
Change-Id: Ieea801ceb8082349858a3fa8c4d324b6ad6278fb
diff --git a/services/tests/wmtests/src/com/android/server/wm/WindowTestsBase.java b/services/tests/wmtests/src/com/android/server/wm/WindowTestsBase.java
index 07244a4..0fcf987 100644
--- a/services/tests/wmtests/src/com/android/server/wm/WindowTestsBase.java
+++ b/services/tests/wmtests/src/com/android/server/wm/WindowTestsBase.java
@@ -359,9 +359,12 @@
                     new InsetsFrameProvider(owner, 0, WindowInsets.Type.tappableElement()),
                     new InsetsFrameProvider(owner, 0, WindowInsets.Type.mandatorySystemGestures())
             };
-            for (int rot = Surface.ROTATION_0; rot <= Surface.ROTATION_270; rot++) {
-                mNavBarWindow.mAttrs.paramsForRotation[rot] =
-                        getNavBarLayoutParamsForRotation(rot, owner);
+            // If the navigation bar cannot move then it is always at the bottom.
+            if (mDisplayContent.getDisplayPolicy().navigationBarCanMove()) {
+                for (int rot = Surface.ROTATION_0; rot <= Surface.ROTATION_270; rot++) {
+                    mNavBarWindow.mAttrs.paramsForRotation[rot] =
+                            getNavBarLayoutParamsForRotation(rot, owner);
+                }
             }
         }
         if (addAll || ArrayUtils.contains(requestedWindows, W_DOCK_DIVIDER)) {