Replace uname -m with rpm --query for userspace arch detection

[mmm-choi]

Summary

Replace $(uname -m) with rpm --query --queryformat='%{ARCH}' rpm in all AL2 and AL2023 Dockerfiles.

Motivation

Addresses feedback from @tianon on PR #21053:

1. uname -m reports kernel architecture, which doesn't necessarily match the userspace architecture. Using rpm --query queries the actual userspace architecture, which is more correct for RPM-based images.

2. Capture architecture in a variable before use — inline $(uname -m) subshells can swallow errors. Capturing ARCH early in the && chain ensures proper error propagation under set -eux.

Changes

• Added ARCH="$(rpm --query --queryformat='%{ARCH}' rpm)" early in the RUN command chain (right after set -eux)
• Replaced all $(uname -m) occurrences with ${ARCH}
• 24 Dockerfiles modified across Corretto 8, 11, 17, 21, 25, 26 (all AL2 and AL2023 variants)

Not Modified

• Alpine Dockerfiles (use apk add, no uname -m)
• Debian Dockerfiles (use apt-get, no uname -m)
• al2-generic Dockerfiles (use yum install from repo, no direct RPM downloads)
• slim Dockerfiles (use package managers)

Testing

• Built and verified java -version on AL2 (11/jdk/al2) and AL2023 (17/jdk/al2023, 8/jre/al2023) images
• All container-structure-tests pass
• Confirmed zero remaining uname -m in any AL2/AL2023 Dockerfile