RFR: 8340194: Replace usage of -ms with -Xms in LauncherCommon.gmk make file

[Jaikiran Pai]

Can I please get a review of this trivial change in the `LauncherCommon.gmk` file which replaces the use of the outdated `-ms` option with `-Xms`?

This is a cleanup prior to the effort of deprecating the outdated `-ms` launcher option for removal.

Local build on a macosx M1 passed with this change. CI build against various platforms is currently in progress.

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Commit messages:
 - 8340194: Replace usage of -ms with -Xms in LauncherCommon.gmk make file

Changes: https://git.openjdk.org/jdk/pull/21017/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=21017&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8340194
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/21017.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21017/head:pull/21017

PR: https://git.openjdk.org/jdk/pull/21017