Implement new API of external display settings (1/2)

- Using DisplaySettings class for storing the display settings.
- Define flags in WindowManager.
- Have direct IWindowManager APIs to set and change display settings at
  runtime.
- Mark TODO to original usage of the flags.
- Add test case of DisplaySettings.
- Expose some APIs for CTS usage.

Bug: 114338689
Test: atest DisplayWindowSettingsTests
Test: atest CtsApacheHttpLegacy27ApiSignatureTestCases
Change-Id: I64ed14866d45cd5817fc3c895b6110c79c37b0ad
diff --git a/services/core/java/com/android/server/wm/DisplayContent.java b/services/core/java/com/android/server/wm/DisplayContent.java
index e20793e..b01d67d 100644
--- a/services/core/java/com/android/server/wm/DisplayContent.java
+++ b/services/core/java/com/android/server/wm/DisplayContent.java
@@ -2132,7 +2132,7 @@
         if (density == mInitialDisplayDensity) {
             density = 0;
         }
-        mService.mDisplaySettings.setForcedDensity(this, density, userId);
+        mService.mDisplayWindowSettings.setForcedDensity(this, density, userId);
     }
 
     /** @param mode {@link #FORCE_SCALING_MODE_AUTO} or {@link #FORCE_SCALING_MODE_DISABLED}. */
@@ -2145,7 +2145,7 @@
         Slog.i(TAG_WM, "Using display scaling mode: " + (mDisplayScalingDisabled ? "off" : "auto"));
         mService.reconfigureDisplayLocked(this);
 
-        mService.mDisplaySettings.setForcedScalingMode(this, mode);
+        mService.mDisplayWindowSettings.setForcedScalingMode(this, mode);
     }
 
     /** If the given width and height equal to initial size, the setting will be cleared. */
@@ -2167,7 +2167,7 @@
         if (clear) {
             width = height = 0;
         }
-        mService.mDisplaySettings.setForcedSize(this, width, height);
+        mService.mDisplayWindowSettings.setForcedSize(this, width, height);
     }
 
     void getStableRect(Rect out) {