Redirects to Form Start onBackPressed and clicking anywhere

#### Software and hardware versions
Collect debug build variant
Galaxy Nexus API 24

#### Problem description
A) When opening a saved form, and you press back button instead of going back to the list of forms, you're taken back to the start of form.
B) Secondly, when you open a form and you touch anywhere on the screen except the buttons, you'll be redirected to the start of the form.
#### Steps to reproduce the problem
**A:**
1) Go to Edit Saved Forms
2) Open a Form
3) Press back button
4) You'll be taken back to the start of form.

**B:**
1) Go to Edit Saved Forms
2) Open a Form
3) Touch on the anywhere on the screen except the buttons i..e touch the ```Welcome to ODK``` textview.
4) You'll be redirected to the start of form
#### Expected behavior
A) You should be taken back to the list of saved forms when pressing back.
B) No action should take place when touching on the screen.

#### GIF:
### **For A)**

### **For B)**

#### Other information
Things you tried, stack traces, related issues, suggestions on how to fix it...

Reproduce the issue from Edit Saved Forms on the reported Android configuration, following both the back-button and screen-touch steps. Trace the saved-form screen's navigation and touch handling; done means Back returns to the saved-forms list and touching non-button content performs no action.

Written by the indexing model from the issue text.