Fix corner rounding.

Signal/src/ViewControllers/ConversationView/Cells/OWSBubbleView.m

@@ -7,7 +7,7 @@
 
 NS_ASSUME_NONNULL_BEGIN
 
-const CGFloat kOWSMessageCellCornerRadius = 18;
+const CGFloat kOWSMessageCellCornerRadius = 16;
 
 @interface OWSBubbleView ()
 

Signal/src/ViewControllers/ConversationView/Cells/OWSMessageBubbleView.m

@@ -76,8 +76,6 @@ NS_ASSUME_NONNULL_BEGIN
     self.stackView = [UIStackView new];
     self.stackView.axis = UILayoutConstraintAxisVertical;
     self.stackView.alignment = UIStackViewAlignmentFill;
-    [self addSubview:self.stackView];
-    [self.stackView autoPinEdgesToSuperviewEdges];
 
     self.bodyTextView = [self newTextView];
     // Setting dataDetectorTypes is expensive.  Do it just once.
@@ -260,6 +258,9 @@ NS_ASSUME_NONNULL_BEGIN
     CGSize bodyMediaContentSize = [self bodyMediaSize];
     CGSize bodyTextContentSize = [self bodyTextSizeWithIncludeMargins:NO];
 
+    [self.bubbleView addSubview:self.stackView];
+    [self.viewConstraints addObjectsFromArray:[self.stackView autoPinEdgesToSuperviewEdges]];
+
     if ([self.viewItem.interaction isKindOfClass:[TSMessage class]] && self.hasBubbleBackground) {
         TSMessage *message = (TSMessage *)self.viewItem.interaction;
         self.bubbleView.bubbleColor = [self.bubbleFactory bubbleColorWithMessage:message];