fix: Correct selection of menu item in Navigation drawer

[kush-mish]

Fixes #1383

Checklist:

• I have checked for PMD and check-style issues
• I have read the Contribution & Best practices Guide and my PR follows them.
• My branch is up-to-date with the Upstream development branch.

Note: This bug was not afflicting only the Attendees fragment having the Activity Log as a subfragment but, every other fragment having subfragments.

Changes: Correct menu item is selected in Navigation drawer even when the back button is pressed from a subfragment.

Screenshot after the change:

[ci-reporter]

The build is failing

✨ Good work on this PR so far! ✨ Unfortunately, the Circle CI build is failing as of 962cd2b. Here's the output:

Test Coverage

registerResGeneratingTask is deprecated, use registerGeneratedResFolders(FileCollection)

I'm sure you can fix it! If you need help, don't hesitate to ask a maintainer of the project!

---

This comment was automagically generated by ci-reporter. If you see a problem, open an issue here.

[ci-reporter]

The build is failing

✨ Good work on this PR so far! ✨ Unfortunately, the Circle CI build is failing as of 962cd2b. Here's the output:

Test Coverage

registerResGeneratingTask is deprecated, use registerGeneratedResFolders(FileCollection)

I'm sure you can fix it! If you need help, don't hesitate to ask a maintainer of the project!

---

This comment was automagically generated by ci-reporter. If you see a problem, open an issue here.

[kush-mish]

@iamareebjamal, please help me with the test

[iamareebjamal]

Tests are failing. Fix them

[kush-mish]

The testBack() function in FragmentNavigator.java is asserting that the dashboard should be active after pressing back, which seems implausible since when inside a subfragment pressing back will lead to the fragment and not the dashboard.
https://github.com/fossasia/open-event-orga-app/blob/c116c294992905348b3bbc1b6a057fe31e382b3c/app/src/test/java/com/eventyay/organizer/core/main/FragmentNavigatorTest.java#L111-L129
That's why line 126 is causing error.

[iamareebjamal]

True, add a test case for that and fix this issue

[codecov]

Codecov Report

Merging #1416 into development will increase coverage by <.01%.
The diff coverage is 50%.

@@               Coverage Diff                @@
##             development   #1416      +/-   ##
================================================
+ Coverage          24.29%   24.3%   +<.01%     
  Complexity           757     757              
================================================
  Files                237     237              
  Lines               8718    8720       +2     
  Branches             352     353       +1     
================================================
+ Hits                2118    2119       +1     
  Misses              6517    6517              
- Partials              83      84       +1

Impacted Files	Coverage Δ	Complexity Δ
...com/eventyay/organizer/core/main/MainActivity.java	0% <0%> (ø)	0 <0> (ø)	⬇️
...ventyay/organizer/core/main/FragmentNavigator.java	39.65% <80%> (+0.36%)	6 <1> (ø)	⬇️

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[iamareebjamal]

No if statements in tests