Remove unnecessary boxing in AutoValue classes #4706

Job	Run time
Validate Dagger version	14s
Bazel build	7m 13s
Bazel tests	19m 42s
Artifact Android local tests (AGP 7.0.0)	6m 45s
Artifact Android emulator tests (API ${{ matrix.api-level }})	0s
Artifact Android local tests (AGP 7.1.2)	6m 54s
Artifact verification tests	15m 12s
Artifact Java local tests	5m 30s
Artifact Android local tests (AGP 8.1.0)	1m 2s
Build Hilt Gradle plugin against latest AGP version	0s
Test Hilt Gradle plugin	10m 24s
Clean up GitHub Action caches	6s
Publish snapshot	0s
	1h 13m 2s

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