Closes #3217 NullPointerException at ContributionsFragment.onAuthCookieAcquire when starting the app after a few hours

[ashishkumar468]

Description (required)

Fixes #3217 NullPointerException at ContributionsFragment.onAuthCookieAcquire when starting the app after a few hours

What changes did you make and why?
uploadServiceIntent throws null pointer exception onActivity recreation
Tests performed (required)

Tested ProdDebug} on Pixel2 with API level 27.

[tests-checker]

Could you please add tests to make sure this change works as expected?

[codecov-io]

Codecov Report

Merging #3220 into master will decrease coverage by <.01%.
The diff coverage is 0%.

@@            Coverage Diff            @@
##           master   #3220      +/-   ##
=========================================
- Coverage    6.22%   6.22%   -0.01%     
=========================================
  Files         264     264              
  Lines       11205   11208       +3     
  Branches      851     850       -1     
=========================================
  Hits          698     698              
- Misses      10450   10453       +3     
  Partials       57      57

Impacted Files	Coverage Δ
...w/commons/contributions/ContributionsFragment.java	0% <0%> (ø)	⬆️
...r/free/nrw/commons/contributions/MainActivity.java	0% <0%> (ø)	⬆️

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[neslihanturan]

I didn't reproduce this issue but, null checking should be fine.