Read *.rc files from flattened APEX

This change fixes a bug that *.rc files in APEXes are not read when the
APEXes are flattened. This was because init used "/apex/*@*/etc/*.rc"
glob pattern to find the files, which gives 0 result with flattened
APEXes; with flattend APEXes /system/apex is just bind-mounted to /apex,
and therefore, the name@version directories don't exist.

Fixing the issue by globing /apex/*/etc/*.rc and filter-out the paths
with @ to avoid double parsing the *.rc files in case of non-flattend
APEXes.

Bug: 134067086
Test: revert I75ec6b69cca1cef071b50fac9a4cf8b8ceddb142
build sdk_gphone_x86_64 and record a video in the camera app.
The recording works. `ps -A | grep media.swcodec` shows media.swcodec process.
`atest CtsStatsdHostTestCases:android.cts.statsd.atom.UidAtomTests#testAudioState` passes
Test: build sdk_phone_x86_64 and do the same.

Change-Id: I00af1910a8e8a330addc4c6903e5f3695aeb6865