docs: fix secret env keys on ObjectBucketClaim
docs: fix secret env keys on ObjectBucketClaim

The documentation on the Ceph ObjectBucketClaim CRD
erroneously states that the generated Secret resource
contains keys `ACCESS_KEY_ID`, `SECRET_ACCESS_KEY`.

According to ceph-object.md, and when mounting the secret
into a container via secretRef, or inspecting it with kubectl,
the variables have an `AWS_` prefix.
Like so: `AWS_ACCESS_KEY_ID`, `AWS_SECRET_ACCESS_KEY`.

This commit adds the `AWS_` prefix to both keys.

Signed-off-by: Richard Patel <b1c1d8736f20db3fb6c1c66bb1455ed43909f0d8@terorie.dev>

rook/rook,rook/rook,rook/nfs,rook/nfs,rook/rook,rook/rook,rook/nfs,rook/rook