[Chips] When deleting text in MDCChipField, only select the last chip…

… if the text field is empty.

This change moves the textField length check before the character deletion (previously it happened after), so the last chip in the field is only selected if the user taps the delete key when there is no text entered in the field.

PiperOrigin-RevId: 306522550

components/Chips/src/MDCChipField.m

@@ -63,10 +63,10 @@ - (CGRect)textRectForBounds:(CGRect)bounds {
 #pragma mark UIKeyInput
 
 - (void)deleteBackward {
-  [super deleteBackward];
   if (self.text.length == 0) {
     [self.deletionDelegate textFieldShouldRespondToDeleteBackward:self];
   }
+  [super deleteBackward];
 }
 
 #if MDC_CHIPFIELD_PRIVATE_API_BUG_FIX && \