Use application context when fetching shared prefs.

Using non-application contexts incurs extra disk access because shared prefs are cached per context.

Test: manually ejected sim and observed no strict mode violations
PiperOrigin-RevId: 183739285
Change-Id: I9337e226ae1e060478219cf495752ceccf5a31e6
diff --git a/java/com/android/voicemail/impl/OmtpService.java b/java/com/android/voicemail/impl/OmtpService.java
index 4e8860c..e10a275 100644
--- a/java/com/android/voicemail/impl/OmtpService.java
+++ b/java/com/android/voicemail/impl/OmtpService.java
@@ -197,14 +197,14 @@
   }
 
   private static void setShuttingDown(Context context, boolean value) {
-    PreferenceManager.getDefaultSharedPreferences(context)
+    PreferenceManager.getDefaultSharedPreferences(context.getApplicationContext())
         .edit()
         .putBoolean(IS_SHUTTING_DOWN, value)
         .apply();
   }
 
   private static boolean isShuttingDown(Context context) {
-    return PreferenceManager.getDefaultSharedPreferences(context)
+    return PreferenceManager.getDefaultSharedPreferences(context.getApplicationContext())
         .getBoolean(IS_SHUTTING_DOWN, false);
   }
 }
diff --git a/java/com/android/voicemail/impl/VisualVoicemailPreferences.java b/java/com/android/voicemail/impl/VisualVoicemailPreferences.java
index 72506eb..1d7204e 100644
--- a/java/com/android/voicemail/impl/VisualVoicemailPreferences.java
+++ b/java/com/android/voicemail/impl/VisualVoicemailPreferences.java
@@ -31,7 +31,7 @@
     super(
         context,
         phoneAccountHandle,
-        PreferenceManager.getDefaultSharedPreferences(context),
+        PreferenceManager.getDefaultSharedPreferences(context.getApplicationContext()),
         "visual_voicemail_");
   }
 }