Update the wiki bazel instructions to add some tips around python and…

… jdk8 (#5159)

<!-- READ ME FIRST: Please fill in the explanation section below and
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## Explanation
Update the bazel setup instructions wiki to add some tips/workarounds
from my recent experience. Also, I added the instructions for Linux and
Mac to the side panel, since Windows was already there.

## Essential Checklist
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- [ ] The PR title and explanation each start with "Fix #bugnum: " (If
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#bugnum: ...".)
- [ ] Any changes to
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- [x] The PR follows the [style
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- [x] The PR does not contain any unnecessary code changes from Android
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## For UI-specific PRs only
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- Add screenshots for portrait/landscape for both a tablet & phone of
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---------

Co-authored-by: Adhiambo Peres <[email protected]>

wiki/Bazel-Setup-Instructions-for-Linux.md

@@ -25,10 +25,16 @@ Oppia Android also requires OpenJDK 8. The Bazel installation instructions above
 
    You can confirm that this is set up using the command `java -version`, which should result in three lines being printed out with the first one showing "openjdk version "1.8.0_292".
 
+> **Tip:** Newer linux distributions may not have openjdk-8 anymore. This has been reported for Debian and Ubuntu. If this is your case, **openjdk-11** has been tested as a viable alternative.
+
 ### 3. Install Python 2
 
 Ensure that you have Python 2 installed and make sure that it is currently active on your environment. You can do this by using the ``python --version`` command which should show Python 2.X.X. If it doesn’t, click [here](https://linuxconfig.org/install-python-2-on-ubuntu-20-04-focal-fossa-linux) for a resource on how to install and update Linux to use Python 2.
 
+> **Tip:** Newer linux distributions may not have the python command and instead use python2 and python3. Bazel <5 requires `python` and that [cannot be configured](https://stackoverflow.com/questions/62802126/how-to-stop-bazel-from-relying-on-python2). Creating an alias won't solve the problem, you'll need a symlink. To create one, you can run the following:
+>
+> `sudo apt install python-is-python2`
+
 ### 4. Set up the ANDROID_HOME environment variable
 
 Ensure that your `ANDROID_HOME` environment variable is set to the location of your Android SDK. To do this, find the path to the installed SDK using Android Studio’s SDK Manager (install SDK 28). Assuming the SDK is installed to default locations, you can use the following commands to set the `ANDROID_HOME` variable:<br>

wiki/_Sidebar.md

@@ -15,6 +15,8 @@
     * [Overview of the Oppia Android codebase and architecture](https://github.com/oppia/oppia-android/wiki/Overview-of-the-Oppia-Android-codebase-and-architecture)
   * Bazel
     * [Bazel setup instructions](https://github.com/oppia/oppia-android/wiki/Oppia-Bazel-Setup-Instructions)
+    * [Bazel Setup Instructions for Linux](https://github.com/oppia/oppia-android/wiki/Bazel-Setup-Instructions-for-Linux)
+    * [Bazel Setup Instructions for Mac](https://github.com/oppia/oppia-android/wiki/Bazel-Setup-Instructions-for-Mac)
     * [Bazel Setup Instructions for Windows](https://github.com/oppia/oppia-android/wiki/Bazel-Setup-Instructions-for-Windows)
   * Key Workflows
     * [Guidance on submitting a PR](https://github.com/oppia/oppia-android/wiki/Guidance-on-submitting-a-PR)