Investigate Android sound code issues reported by Codacy

**Describe the bug**

Codacy complains that the following variable is not used (and I don't see that this is false):

https://github.com/jamulussoftware/jamulus/blob/a9deb2259161b6cb86c12259f3e6f398189029ef/android/sound.cpp#L150

Also this warning:

I assume this is a false positive?
**To Reproduce**

See https://app.codacy.com/gh/ann0see/jamulus/file/68862695471/issues/source?bid=21822857&fileBranchId=21822857

**Expected behavior**

No Codacy warnings

**Screenshots**

See above

**Operating system**

Android

**Version of Jamulus**

Latest

**Additional context**

@j-santander @sthenos could you please have a look at these warnings too?

Start by inspecting android/sound.cpp around line 150 and review the two warnings in the linked Codacy report. Determine whether the variable is genuinely unused and whether the second warning is a false positive. Done means the relevant warnings are resolved or justified and Codacy reports no remaining warnings for this code.

Written by the indexing model from the issue text.