Build: verify the runtime inputs only after the session scripts are staged (#504)

With parallel task execution, verifyRuntimeInputs and stageSessionScripts could run at the
same time; main's build at 3d50e6b1 hashed droiddeck-netmanager mid-copy and failed with
'Missing or changed runtime input'. The check now runs after the staging tasks.

app/build.gradle

@@ -214,6 +214,10 @@ tasks.named('preBuild').configure { dependsOn(stageRuntimeAssets) }
 // Unit tests and previews remain usable without Docker. Packaging an APK requires the complete
 // runtime payload prepared by the local helper or CI, with matching sources and output hashes.
 def verifyRuntimeInputs = tasks.register('verifyRuntimeInputs', Exec) {
+    // The session scripts are re-copied into the asset tree by stageSessionScripts; with parallel
+    // task execution this check once hashed a file mid-copy and failed a main build. Hash only
+    // once the staging has finished.
+    mustRunAfter(stageSessionScripts, stageRuntimeAssets)
     workingDir rootProject.projectDir
     commandLine 'python3', 'tools/release/runtime_inputs.py', 'verify'
 }