Streamline SystemUI proguard flags

Remove several unnecessary top-level class keep rules, and inline
@Keep annotations for animatable property accessors.

Bug: 196084106
Test: m SystemUI (yields identical binary)
Change-Id: I3b820a59214d2fdc8e94c38c4317a4e5f44a397f

packages/SystemUI/proguard.flags

@@ -1,20 +1,3 @@
--keep class com.android.systemui.navigationbar.buttons.KeyButtonView {
-  public float getDrawingAlpha();
-  public void setDrawingAlpha(float);
-}
-
--keep class com.android.systemui.navigationbar.buttons.KeyButtonRipple {
-  public float getGlowAlpha();
-  public float getGlowScale();
-  public void setGlowAlpha(float);
-  public void setGlowScale(float);
-}
-
--keep class com.android.systemui.settings.brightness.BrightnessSliderView {
-  public float getSliderScaleY();
-  public void setSliderScaleY(float);
-}
-
 -keep class com.android.systemui.recents.OverviewProxyRecentsImpl
 -keep class com.android.systemui.statusbar.car.CarStatusBar
 -keep class com.android.systemui.statusbar.phone.StatusBar

packages/SystemUI/src/com/android/systemui/navigationbar/buttons/KeyButtonRipple.java

@@ -34,6 +34,8 @@ import android.view.View;
 import android.view.ViewConfiguration;
 import android.view.animation.Interpolator;
 
+import androidx.annotation.Keep;
+
 import com.android.systemui.R;
 import com.android.systemui.animation.Interpolators;
 
@@ -184,19 +186,27 @@ public class KeyButtonRipple extends Drawable {
         }
     }
 
+    /** Gets the glow alpha, used by {@link android.animation.ObjectAnimator} via reflection. */
+    @Keep
     public float getGlowAlpha() {
         return mGlowAlpha;
     }
 
+    /** Sets the glow alpha, used by {@link android.animation.ObjectAnimator} via reflection. */
+    @Keep
     public void setGlowAlpha(float x) {
         mGlowAlpha = x;
         invalidateSelf();
     }
 
+    /** Gets the glow scale, used by {@link android.animation.ObjectAnimator} via reflection. */
+    @Keep
     public float getGlowScale() {
         return mGlowScale;
     }
 
+    /** Sets the glow scale, used by {@link android.animation.ObjectAnimator} via reflection. */
+    @Keep
     public void setGlowScale(float x) {
         mGlowScale = x;
         invalidateSelf();

packages/SystemUI/src/com/android/systemui/settings/brightness/BrightnessSliderView.java

@@ -27,6 +27,7 @@ import android.view.View;
 import android.widget.FrameLayout;
 import android.widget.SeekBar.OnSeekBarChangeListener;
 
+import androidx.annotation.Keep;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 
@@ -183,6 +184,7 @@ public class BrightnessSliderView extends FrameLayout {
      *
      * Used in {@link com.android.systemui.qs.QSAnimator}.
      */
+    @Keep
     public void setSliderScaleY(float scale) {
         if (scale != mScale) {
             mScale = scale;
@@ -199,6 +201,7 @@ public class BrightnessSliderView extends FrameLayout {
         }
     }
 
+    @Keep
     public float getSliderScaleY() {
         return mScale;
     }