Remove end check in favor of checking the resulting source string's content

Author: chipsnyder

aztec/src/main/kotlin/org/wordpress/aztec/AztecText.kt

@@ -632,7 +632,7 @@ open class AztecText : AppCompatEditText, TextWatcher, UnknownHtmlSpan.OnUnknown
 
         val emptyEditTextBackspaceDetector = InputFilter { source, start, end, dest, dstart, dend ->
             if (selectionStart == 0 && selectionEnd == 0
-                    && end == 1 && start == 0
+                    && start == 0
                     && dstart == 0 && dend == 0
                     && isCleanStringEmpty(source)
                     && !isHandlingBackspaceEvent) {
@@ -656,7 +656,11 @@ open class AztecText : AppCompatEditText, TextWatcher, UnknownHtmlSpan.OnUnknown
     }
 
     private fun isCleanStringEmpty(text: CharSequence): Boolean {
-        return (text.count() == 1 && text[0] == Constants.END_OF_BUFFER_MARKER)
+        if( isInGutenbergMode ) {
+            return (text.count() == 1 && text[0] == Constants.END_OF_BUFFER_MARKER)
+        } else {
+            return text.count() == 0
+        }
     }
 
     private fun handleBackspaceAndEnter(event: KeyEvent): Boolean {