[r-mr1] common: Set qti-headers kernel version via soong

[ix5]

This change will allow multiple kernel versions to live side-by-side in one AOSP tree.

Needs to be accompanied by changes to kernel-headers repos to change module name to qti_kernel_headers_X.Y and an auxiliary module to resolve qti_kernel_headers to the correct module.

Overview:

• https://github.com/sonyxperiadev/device-sony-common/pull/839
• https://github.com/sonyxperiadev/device-sony-common-headers/pull/16
• https://github.com/sonyxperiadev/device-sony-common-headers/pull/15
• https://github.com/ix5/qti-headers (to be forked and then placed into kernel/sony/qti-headers)