Werk #13735: check_mk_agent.solaris: Use "/usr/xpg4/bin/grep" if available

Component	Checks & agents
Title	check_mk_agent.solaris: Use "/usr/xpg4/bin/grep" if available
Date	Sep 6, 2022
Level	Trivial Change
Class	Bug Fix
Compatibility	Compatible - no manual interaction needed
Checkmk versions & editions	2.2.0b1 Checkmk Community, Checkmk Pro, Checkmk Ultimate, Checkmk Ultimate MT 2.1.0p12 Checkmk Community, Checkmk Pro, Checkmk Ultimate MT

To the list of all Werks