Fix debug bundle temp file creation on Android

Use app-provided cache directory for os.CreateTemp instead of
os.TempDir() which resolves to /data/local/tmp/ on Android — a
directory not writable by regular apps.

Thread TempDir through GeneratorDependencies -> BundleGenerator and
MobileDependency -> EngineConfig so the Android client can pass its
cache directory from PlatformFiles.CacheDir().

client/android/platform_files.go

@@ -7,4 +7,5 @@ package android
 type PlatformFiles interface {
 	ConfigurationFilePath() string
 	StateFilePath() string
+	CacheDir() string
 }