AtlasDetDescr: is_muon checks.

In the muon subsystem checks is_rpc, etc, we first need to ensure that is_muon passes. Otherwise, we can crash if called for a non-muon identifier.

This merge request affects 1 package:

• DetectorDescription/AtlasDetDescr

Adding @nkoehler ,@rbianchi as watchers

added Geometry master review-pending-level-1 labels

CI Result SUCCESS (hash 97f78e97)

	Athena	AthSimulation	AnalysisBase	AthGeneration
externals
cmake
make
required tests
optional tests

Full details available on this CI monitor view
Athena: number of compilation errors 0, warnings 0
AthSimulation: number of compilation errors 0, warnings 0
AnalysisBase: number of compilation errors 0, warnings 0
AthGeneration: number of compilation errors 0, warnings 0
For experts only: Jenkins output [CI-MERGE-REQUEST-CC7 15193]

added review-approved label and removed review-pending-level-1 label

merged

mentioned in commit 7edeb317

added sweep:ignore label