[fenix] Clear button (https://github.com/mozilla-mobile/fenix/pull/13842)

Co-authored-by: Darren <finchdarren25@gmail.com>

app/src/main/java/org/mozilla/fenix/utils/ClearableEditText.kt

@@ -46,7 +46,9 @@ class ClearableEditText @JvmOverloads constructor(
      * Displays a clear icon if text has been entered.
      */
     override fun onTextChanged(text: CharSequence?, start: Int, lengthBefore: Int, lengthAfter: Int) {
-        val drawable = if (shouldShowClearButton(lengthAfter)) {
+        // lengthAfter has inconsistent behaviour when there are spaces in the entered text, so we'll use text.length.
+        val textLength = text?.length ?: 0
+        val drawable = if (shouldShowClearButton(textLength)) {
             AppCompatResources.getDrawable(context, R.drawable.ic_clear)?.apply {
                 colorFilter = createBlendModeColorFilterCompat(context.getColorFromAttr(R.attr.primaryText), SRC_IN)
             }