Add logic to address Gboard's unusual invocation of TextWatcher methods

Note: This is probably not enough, since this only addresses when the
caret is at the end of the word, but Gboard may exhibit the unusual
behavior also when the caret is in the middle or start of the word.

packages/react-native-aztec/android/src/main/kotlin/org/wordpress/mobile/ReactNativeAztec/EnterPressedWatcher.kt

@@ -24,6 +24,9 @@ class EnterPressedWatcher(aztecText: AztecText, var enterDeleter: EnterDeleter)
     private var selEnd: Int = 0
     var done = false
 
+    private var gboardReplacement: CharSequence? = null
+
+
     override fun beforeTextChanged(text: CharSequence, start: Int, count: Int, after: Int) {
         val aztecText = aztecTextRef.get()
         if (aztecText?.getAztecKeyListener() != null && !aztecText.isTextChangedListenerDisabled()) {
@@ -32,6 +35,13 @@ class EnterPressedWatcher(aztecText: AztecText, var enterDeleter: EnterDeleter)
             this.start = start
             this.selStart = aztecText.selectionStart
             this.selEnd = aztecText.selectionEnd
+
+            if (selStart == selEnd && 0 < count && count < after) {
+                // possible gboard replacement detected
+                gboardReplacement = text.subSequence(start, start + count)
+            } else {
+                gboardReplacement = null
+            }
         }
     }
 
@@ -40,14 +50,25 @@ class EnterPressedWatcher(aztecText: AztecText, var enterDeleter: EnterDeleter)
         val aztecKeyListener = aztecText?.getAztecKeyListener()
         if (aztecText != null && !aztecText.isTextChangedListenerDisabled() && aztecKeyListener != null) {
             val newTextCopy = SpannableStringBuilder(text)
+
+            var gboardOffset = this.start
+            // If gboard replacement is happening, we offset the start position by the length
+            // of the gboard replacement
+            if (gboardReplacement != null) {
+                val gboardRestored = newTextCopy.subSequence(start, start + before)
+                if (gboardRestored.toString() == gboardReplacement.toString()) {
+                    gboardOffset += gboardRestored.length
+                }
+            }
+
             // if new text length is longer than original text by 1
             if (textBefore?.length == newTextCopy.length - 1) {
                 // now check that the inserted character is actually a NEWLINE
-                if (newTextCopy[this.start] == Constants.NEWLINE) {
+                if (newTextCopy[gboardOffset] == Constants.NEWLINE) {
                     done = false
                     aztecText.editableText.setSpan(EnterPressedUnderway(), 0, 0, Spanned.SPAN_USER)
                     aztecKeyListener.onEnterKey(
-                            newTextCopy.replace(this.start, this.start + 1, ""),
+                            newTextCopy.replace(gboardOffset, gboardOffset + 1, ""),
                             true,
                             selStart,
                             selEnd
@@ -61,9 +82,12 @@ class EnterPressedWatcher(aztecText: AztecText, var enterDeleter: EnterDeleter)
         aztecTextRef.get()?.editableText?.getSpans(0, 0, EnterPressedUnderway::class.java)?.forEach {
             if (!done) {
                 done = true
-                if (enterDeleter.shouldDeleteEnter())
-                    text.replace(start, start + 1, "")
+                if (enterDeleter.shouldDeleteEnter()) {
+                    var gboardOffset = start
+                    gboardReplacement?.let { replacement -> gboardOffset += replacement.length }
+                    text.replace(gboardOffset, gboardOffset + 1, "")
                 }
+            }
             aztecTextRef.get()?.editableText?.removeSpan(it)
         }
     }