Cmake android mission custom build features

[DonLakeFlyer]

Various things which need to be supported by cmake custom builds through some sort of override mechanism. Links the Herelink QGC which is currently hacked upstream to make these things work. Once these things are support through cmake the upstream hacks should be removed and custom Herelink cmake files should be updated.

• Downgrade usb lib to version 12
  • Herelink uses older android version - https://github.com/DonLakeFlyer/Herelink-QGC/blob/master/android/build.gradle#L22
• Downgrade android sdk version
  • Herelink needs to download sdk version - https://github.com/DonLakeFlyer/Herelink-QGC/blob/master/CMakeLists.txt#L347
• Things which were support by old android.pri (https://github.com/DonLakeFlyer/Herelink-QGC-Save/blob/master/android.pri):
  • Set package name
  • Support setting of the android Home App
  • Override entire AndroidManifest.xml
  • Other resource overrides

[HTRamsey]

• The android core version has been lowered to 1.12.0
• I think we can change the min SDK to 25 instead of 26, don't remember 100% the reasons 26 was chosen, I want to say the other version I remember being the bare minimum is 24.
• I believe there are a couple of changes in 6.7 that relate to these, such as removing package name from the AndroidManifest. Need to make other changes for customization of AndroidManifest features section and such

[DonLakeFlyer]

• I think we can change the min SDK to 25 instead of 26

If I remember correctly because Qt docs for 6.6 say that 26 is the minimum