Use -language-version 1.9 in the kotlinKythe build rule

There are some instances of .kt code in android platform that are not
fully compatible with kotlinc > 2. To account for this version skew when
generating xrefs, implicitly add `-language-version 1.9` to the args in
the .kzip file. The main kotlinc build rules remain the same.

This value has been picked manually by running
`external/kotlinc/bin/kotlinc -version` at ToT

Bug: 265428637
Test: verified that `-language-version 1.9` is added to the build
command of the .kzip files
Test: ran the indexer locally on the .kzip of `PermissionController-lib`
(this android_library contains .kt code that does not compile with
verison >2)

Change-Id: Icfb72800404d83f63204de23a1ec34b40ee05847