Correct null check for end button behavior.

SettingsState.getSettingLocked never returns a null value, so the car_product overlay value of this setting is always ignored. PhoneWindowManager then uses a hardcoded default with undesired behavior for the car. Checking the null indicator on the returned value allows the setting to be initialized properly.

Fixes: 113123033

Test: adb shell input keyevent 6 before and after change, verify desired behavior
Change-Id: Ib2b64331ae986efda6bb961d487e4de023c43d84
diff --git a/packages/SettingsProvider/src/com/android/providers/settings/SettingsProvider.java b/packages/SettingsProvider/src/com/android/providers/settings/SettingsProvider.java
index 63978ba..3d193db 100644
--- a/packages/SettingsProvider/src/com/android/providers/settings/SettingsProvider.java
+++ b/packages/SettingsProvider/src/com/android/providers/settings/SettingsProvider.java
@@ -3285,8 +3285,8 @@
                 if (currentVersion == 133) {
                     // Version 133: Add default end button behavior
                     final SettingsState systemSettings = getSystemSettingsLocked(userId);
-                    if (systemSettings.getSettingLocked(Settings.System.END_BUTTON_BEHAVIOR) ==
-                            null) {
+                    if (systemSettings.getSettingLocked(Settings.System.END_BUTTON_BEHAVIOR)
+                            .isNull()) {
                         String defaultEndButtonBehavior = Integer.toString(getContext()
                                 .getResources().getInteger(R.integer.def_end_button_behavior));
                         systemSettings.insertSettingLocked(Settings.System.END_BUTTON_BEHAVIOR,