feat: spec-first pipeline — build java2spec generator

Extracts service mappings, parcelable wire formats, and typed constants
from Java source files into YAML spec files. Replaces genservicemap,
genparcelspec, and genconstants.

Merges Java-extracted data into existing AIDL-derived specs:
- 72 service mappings → servicemanager/spec.yaml
- Java wire formats → matched by package+type to AIDL parcelables
- 5 LocationProvider constants → android/location/spec.yaml

Author: xaionaro@dx.center

tools/cmd/java2spec/constants.yaml

@@ -0,0 +1,6 @@
+- java_file: location/java/android/location/LocationManager.java
+  pattern: "*_PROVIDER"
+  go_package: location
+  go_type: LocationProvider
+  go_output: android/location/location_provider_gen.go
+  name_transform: strip_suffix:PROVIDER