Document need for public_baseurl to be correctly set.

[michaelkaye]

Type of change

• Feature
• Bugfix
• Technical
• Other : Docs

Content

In #5949 we corrected the public_baseurl for the integration tests in github actions. This PR adds a note to the troubleshooting of integration tests about the similar failure when it occurs locally.

Motivation and context

Docs are good :)

Checklist

• Changes has been tested on an Android device or Android emulator with API 21
• UI change has been tested on both light and dark themes
• Accessibility has been taken into account. See https://github.com/vector-im/element-android/blob/develop/CONTRIBUTING.md#accessibility
• Pull request is based on the develop branch
• Pull request includes a new file under ./changelog.d. See https://github.com/vector-im/element-android/blob/develop/CONTRIBUTING.md#changelog
• Pull request includes screenshots or videos if containing UI changes
• Pull request includes a sign off
• You've made a self review of your PR
• If you have modified the screen flow, or added new screens to the application, you have updated the test UiAllScreensSanityTest.allScreensTest()

[github-actions]

Unit Test Results

122 files  ±0  122 suites  ±0   2m 7s ⏱️ -6s
205 tests ±0  205 ✔️ ±0  0 💤 ±0  0 ❌ ±0 
690 runs  ±0  690 ✔️ ±0  0 💤 ±0  0 ❌ ±0 

Results for commit 2bd89e6. ± Comparison against base commit 0b00f97.

♻️ This comment has been updated with latest results.

[bmarty]

Thanks!

[github-actions]

Matrix SDK

Integration Tests Results:

• [org.matrix.android.sdk.session]
  = passed=15 failures=5 errors=0 skipped=3
• [org.matrix.android.sdk.account]
  = passed=3 failures=0 errors=0 skipped=2
• [org.matrix.android.sdk.internal]
  = passed=93 failures=54 errors=0 skipped=13
• [org.matrix.android.sdk.ordering]
  = passed=93 failures=54 errors=0 skipped=13
• [org.matrix.android.sdk.PermalinkParserTest]
  = passed=2 failures=0 errors=0 skipped=0