Fix #86 unnecessary space in the bottom (#87)

Author: alizbazar

lib/KeyboardAwareMixin.js

@@ -26,7 +26,10 @@ const KeyboardAwareMixin = {
 
   setViewIsInsideTabBar: function (viewIsInsideTabBar: bool) {
     this.viewIsInsideTabBar = viewIsInsideTabBar
-    this.setState({keyboardSpace: _KAM_DEFAULT_TAB_BAR_HEIGHT})
+    const keyboardSpace = viewIsInsideTabBar ? _KAM_DEFAULT_TAB_BAR_HEIGHT : 0
+    if (this.state.keyboardSpace !== keyboardSpace) {
+      this.setState({keyboardSpace})
+    }
   },
 
   setResetScrollToCoords: function (coords: {x: number, y: number}) {