Verify both android libraries reach the APK

[jcant0n]

The README has said it plainly since this morning: "android-arm, android-arm64: not verified. Nothing installs the package on Android today." This is the leg that closes it, ported from Cesium.NET's, where it is green against the real .nupkg.

One APK, both ABIs

Where this differs from Cesium's single-ABI equivalent: the smoke project multi-targets android-arm;android-arm64, so a single build has to put both libraries in the APK —

• lib/armeabi-v7a/libJoltC.so and lib/arm64-v8a/libJoltC.so present,
• each over a megabyte (present-and-empty passes presence and nothing else),
• and no other ABI alongside — a third one means the project asked for a runtime identifier JoltPhysicsC does not build.

The build succeeding proves none of that. A package can carry runtimes/android-*/native and lose them on the way into the APK — which is exactly the class of mistake this package shipped for months on wasm and iOS. So the leg opens the APK and looks.

Verified locally before pushing

APK is 22.2 MB and carries both libraries
  lib/arm64-v8a/libJoltC.so     27.0 MB uncompressed
  lib/armeabi-v7a/libJoltC.so   23.1 MB uncompressed
ABIs: exactly {armeabi-v7a, arm64-v8a}

The README row moves from "not verified" to the same wording as Cesium's, keeping the honest part: the libraries themselves are not executed.

One observation out of scope: those .so are 27 and 23 MB where the wasm archive is 3.7 — they likely carry debug info, the same thing CesiumC's android build stripped from 251 MB to 27. Worth a look in JoltPhysicsC someday; not this PR.

[github-actions]

API gate: additive

Every symbol that existed still exists, unchanged. Nothing that compiled before stops compiling.

Target framework	Added	Removed
net10.0-ios	+0	-0
net10.0	+0	-0

_{Enum and constant values are part of the measured surface: a renumbering keeps compiling and sends the wrong number to the driver, so it counts as a removal.}