Log Message:
volk: updated to 2.5.2

Changes 2.5.2

Android
- Add Android CI
- Fix armeabi-v7a on Android
CI
- Update all test jobs to more recent actions
volk_8u_x4_conv_k7_r2_8u
- Add NEON implementation neonspiral via sse2neon.h
Fixes
- Fix out-of-bounds reads
- Fix broken neon kernels
- Fix float to int conversion
CMake
- Suppress superfluous warning
- Fix Python install path calculation and documentation
cpu_features
- Update submodule pointer
VOLK 3.0 release preparations
- Use SPDX license identifiers everywhere
- Re-arrange files in top-level folder
- Update Doxygen and all Doxygen related tasks into docs