Fix MessageBundle key/file name resolver algorithm #39828

Job	Run time
CI Sanity Check	32s
Attach pull request number	4s
Initial JDK 17 Build	12m 10s
Calculate Test Jobs	10s
Maven Tests - JDK 17	7m 15s
JVM Tests - JDK 17	12m 5s
Maven Tests - JDK 17 Windows	10m 18s
JVM Tests - JDK 21	13m 43s
Devtools Tests - JDK ${{ matrix.java.name }}	0s
Gradle Tests - JDK ${{ matrix.java.name }}	0s
JVM Tests - JDK 17 Windows	18m 40s
Kubernetes Tests - JDK ${{ matrix.java.name }}	0s
Native Tests - Misc1	5m 23s
Quickstarts Compilation - JDK 17	6m 40s
Native Tests - Virtual Thread - Main	3m 36s
Native Tests - Misc2	4m 18s
MicroProfile TCKs Tests	0s
Build report	31s
	1h 35m 25s

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