Update linux/battery module to support both BAT0 and BAT1

[zencrab]

Update linux/battery module to support both BAT0 and BAT1

Description

This PR added support for BAT1 in the linux battery module. For some linux dirstros, such as Arch Linux (which I run) the battery for certain laptop can be BAT1, instead of BAT0 which plyer already supported.

This PR will make plyer battery module work for every linux distribution. Fixing the error I asked to reopen and now Closes #743.

Related Issue(s)

• Related to [Bug] battery.status gives an error. #743
  There might be other issues closed, like this past one but not resolved.

Changes

• Updated linux/battery module to support BAT1.
• Refactored conflicting code in plyer/tests/test_battery.py, which was running assert_called_once_with() and added testing for both BAT0 and BAT1. N.B.: I didn't understand why had to make sure it was called once, please refactor or lemme know.

How Has This Been Tested?

• Ran all unit tests using pytest and confirmed they passed, but TestUniqueID.test_uniqueid which was failing beforehand.
• Performed manual testing on Linux to verify BAT1 work as expected. Need somebody to manually test on a Linux system with BAT0

Screenshots

Checklist

• My code follows the project's style guidelines, I hooked PEP8 before committing.
• I have commented my code, especially in hard-to-understand areas.
• Change documentation is not needed as it doesn't specify the if the battery is BAT0 or BAT1
• My changes generate no new warnings.
• I have added tests to prove my fix or feature works.
• Any dependent changes have been merged and published in downstream modules.

Additional Notes

The only concern is that I had to change the previous test as it required for the battery to only be called once (I don't understand why), the command is one call already.
However, if there is a reason behind it, this my port breaking changes. Please @KeyWeeUsr, let me know if the check for one call is mandatory.