Allow Android enter to eat a space at the end of the line

FIX: Properly recognize Android GBoard enter presses that strip a space at
the end of the line as enter.

Closes codemirror/dev#1312

src/domchange.ts

@@ -124,7 +124,10 @@ export function applyDOMChange(view: EditorView, domChange: DOMChange): boolean
     // events and the pendingAndroidKey mechanism, but that's not
     // reliable in all situations.)
     if (browser.android &&
-        ((change.from == sel.from && change.to == sel.to &&
+        ((change.to == sel.to &&
+          // GBoard will sometimes remove a space it just inserted
+          // after a completion when you press enter
+          (change.from == sel.from || change.from == sel.from - 1 && view.state.sliceDoc(change.from, sel.from) == " ") &&
           change.insert.length == 1 && change.insert.lines == 2 &&
           dispatchKey(view.contentDOM, "Enter", 13)) ||
          ((change.from == sel.from - 1 && change.to == sel.to && change.insert.length == 0 ||