Convert extension functions to regular functions.

An incoming upgrade to dagger 2.50 explicitly prevents using extension
functions in modules: https://aosp.corp.google.com/2893980.

https://github.com/google/dagger/commit/b37cffd6a9bb58c7bbe2f39f53b761168d5235fb

Flag: NA
Fixes: 318405239
Test: m SystemUI
Change-Id: I5c5e34497f6dd05cdb67d7d65ac335db617ebb25
Merged-In: I5c5e34497f6dd05cdb67d7d65ac335db617ebb25