Converge appLaunchTime.

Signal/src/util/OWSOrphanDataCleaner.m

@@ -590,7 +590,7 @@ typedef void (^OrphanDataBlock)(OWSOrphanData *);
     // We need to avoid cleaning up new attachments and files that are still in the process of
     // being created/written, so we don't clean up anything recent.
     const NSTimeInterval kMinimumOrphanAgeSeconds = CurrentAppContext().isRunningTests ? 0.f : 15 * kMinuteInterval;
-    NSDate *appLaunchTime = AppVersion.sharedInstance.appLaunchTime;
+    NSDate *appLaunchTime = CurrentAppContext().appLaunchTime;
     NSTimeInterval thresholdTimestamp = appLaunchTime.timeIntervalSince1970 - kMinimumOrphanAgeSeconds;
     NSDate *thresholdDate = [NSDate dateWithTimeIntervalSince1970:thresholdTimestamp];
     [databaseConnection readWriteWithBlock:^(YapDatabaseReadWriteTransaction *transaction) {

SignalServiceKit/src/Util/AppVersion.h

@@ -14,8 +14,6 @@
 @property (atomic, readonly) NSString *lastCompletedLaunchMainAppVersion;
 @property (atomic, readonly) NSString *lastCompletedLaunchSAEAppVersion;
 
-@property (atomic, readonly) NSDate *appLaunchTime;
-
 - (instancetype)init NS_UNAVAILABLE;
 
 + (instancetype)sharedInstance;

SignalServiceKit/src/Util/AppVersion.m

@@ -43,8 +43,6 @@ NSString *const kNSUserDefaults_LastCompletedLaunchAppVersion_SAE
 - (void)configure {
     OWSAssertIsOnMainThread();
 
-    _appLaunchTime = [NSDate new];
-
     self.currentAppVersion = [[NSBundle mainBundle] objectForInfoDictionaryKey:@"CFBundleShortVersionString"];
     
     // The version of the app when it was first launched.