Move checkSomeDiskSpaceAvailable to Swift

This change should have no user impact.

Signal/src/AppDelegate.m

@@ -244,19 +244,6 @@ static void uncaughtExceptionHandler(NSException *exception)
     return YES;
 }
 
-- (BOOL)checkSomeDiskSpaceAvailable
-{
-    NSString *tempDir = [NSTemporaryDirectory() stringByAppendingPathComponent:[NSUUID new].UUIDString];
-    BOOL succeededCreatingDir = [OWSFileSystem ensureDirectoryExists:tempDir];
-
-    // Best effort at deleting temp dir, which shouldn't ever fail
-    if (succeededCreatingDir && ![OWSFileSystem deleteFile:tempDir]) {
-        OWSFailDebug(@"Failed to delete temp dir used for checking disk space!");
-    }
-
-    return succeededCreatingDir;
-}
-
 - (BOOL)launchToHomeScreen:(NSDictionary *_Nullable)launchOptions instrumentsMonitorId:(unsigned long long)monitorId
 {
     [self setupNSEInteroperation];

Signal/src/AppDelegate.swift

@@ -16,6 +16,21 @@ enum LaunchFailure: UInt {
 }
 
 extension AppDelegate {
+    @objc(checkSomeDiskSpaceAvailable)
+    func checkSomeDiskSpaceAvailable() -> Bool {
+        let tempDir = URL(fileURLWithPath: NSTemporaryDirectory())
+            .appendingPathComponent(UUID().uuidString)
+            .path
+        let succeededCreatingDir = OWSFileSystem.ensureDirectoryExists(tempDir)
+
+        // Best effort at deleting temp dir, which shouldn't ever fail
+        if succeededCreatingDir && !OWSFileSystem.deleteFile(tempDir) {
+            owsFailDebug("Failed to delete temp dir used for checking disk space!")
+        }
+
+        return succeededCreatingDir
+    }
+
     @objc(getActionSheetForLaunchFailure:fromViewController:onContinue:)
     func getActionSheet(for launchFailure: LaunchFailure,
                         from viewController: UIViewController,