chore: build android with vulkan and qualcomm backends

[msluszniak]

Description

This PR adds vulkan and qualcomm backends to the android build.

Introduces a breaking change?

• Yes
• No

Type of change

• Bug fix (change which fixes an issue)
• New feature (change which adds functionality)
• Documentation update (improves or adds clarity to existing documentation)
• Other (chores, tests, code style improvements etc.)

Tested on

• iOS
• Android

Testing instructions

Add android model exported on vulkan / qualcomm and check if it works correctly in our workflow.

Screenshots

Related issues

Checklist

• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have updated the documentation accordingly
• My changes generate no new warnings

Additional notes

[msluszniak]

Confirmed that:

    if (ptr == nullptr)
      ptr = saved_ptr;

in executorch/backends/xnnpack/runtime/XNNWeightsCache.cpp right after void* saved_ptr = context->offset_to_addr(context, offset); is still needed.

[chmjkb]

how does this influence the package size?

[msluszniak]

how does this influence the package size?

This is more an experimental setup right now to run vulkan and qualcomm and test the benefits of both. Ultimately, we are forced to use selective builds before we move with these.