Fix modal presentation issue

Signal/src/ViewControllers/ConversationView/ConversationViewController.m

@@ -3014,6 +3014,7 @@ typedef enum : NSUInteger {
             OWSAssertDebug(pickerModal);
 
             [self dismissKeyBoard];
+            pickerModal.modalPresentationStyle = UIModalPresentationFullScreen;
             [self presentViewController:pickerModal animated:YES completion:nil];
         }];
     }];
@@ -3049,6 +3050,7 @@ typedef enum : NSUInteger {
         pickerModal.sendMediaNavDelegate = self;
 
         [self dismissKeyBoard];
+        pickerModal.modalPresentationStyle = UIModalPresentationFullScreen;
         [self presentViewController:pickerModal animated:YES completion:nil];
     }];
 }

Signal/src/ViewControllers/Photos/ImagePickerController.swift

@@ -58,7 +58,7 @@ class ImagePickerGridController: UICollectionViewController, PhotoLibraryDelegat
 
         // ensure images at the end of the list can be scrolled above the bottom buttons
         let bottomButtonInset = -1 * SendMediaNavigationController.bottomButtonsCenterOffset + SendMediaNavigationController.bottomButtonWidth / 2
-        collectionView.contentInset.bottom = bottomButtonInset + 8
+        collectionView.contentInset.bottom = bottomButtonInset + 16
         view.backgroundColor = .white
 
         // The PhotoCaptureVC needs a shadow behind it's cancel button, so we use a custom icon.