[Android] Fix symbol relocation errors on Android x86

[joseluismarti]

Description

Current Android x86 builds crash at startup with the following message in the logcat:

D AndroidRuntime: Shutting down VM
E AndroidRuntime: FATAL EXCEPTION: main
E AndroidRuntime: Process: org.xbmc.kodi, PID: 5825
E AndroidRuntime: java.lang.UnsatisfiedLinkError: dlopen failed: /data/app/org.xbmc.kodi-1/lib/x86/libkodi.so: has text relocations
...

This occurs because some shared objects contain text relocations. The usual reason for text relocations is non-position independent code written assembler.

We can use the scanelf tool to identify them: scanelf -qT libkodi.so

Fixed by using position independent code in ffmpeg and libass targets.

How has this been tested?

Tested on an Android 7.0 x86 image on Android Emulator

Types of change

• Bug fix (non-breaking change which fixes an issue)
• Clean up (non-breaking change which removes non-working, unmaintained functionality)
• Improvement (non-breaking change which improves existing functionality)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that will cause existing functionality to change)
• Cosmetic change (non-breaking change that doesn't touch code)
• None of the above (please explain below)

Checklist:

• My code follows the Code Guidelines of this project
• My change requires a change to the documentation, either Doxygen or wiki
• I have updated the documentation accordingly
• I have read the Contributing document
• I have added tests to cover my change
• All new and existing tests passed

[joseluismarti]

jenkins build this please