Include soong installs file before Android.mk files

I changed the installs file to be after Android.mk files in
aosp/3080639, in order to minimize the information given to Android.mk
files. But it appears that some exotic vendor builds actually rely
on this information (when they shouldn't).

Bug: 340254841
Test: diff'd out/target/product/<vendor>/installed-files-vendor.txt before/after this cl, and with a revert of aosp/3080639
Change-Id: I00a06fe984397e4dba57352850f5e2484d17f657