feat(prompts): Register android tombstones onboarding prompt

Register the `issue_android_tombstones_onboarding` prompt in the
prompts config so the frontend can use the prompts-activity API to
track dismiss/snooze state for the tombstones onboarding banner.
Scoped per organization and project.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: romtsn

src/sentry/utils/prompts.py

@@ -15,6 +15,7 @@ class _PromptConfig(TypedDict):
     "data_consent_banner": {"required_fields": ["organization_id"]},
     "data_consent_priority": {"required_fields": ["organization_id"]},
     "github_missing_members": {"required_fields": ["organization_id"]},
+    "issue_android_tombstones_onboarding": {"required_fields": ["organization_id", "project_id"]},
     "issue_feedback_hidden": {"required_fields": ["organization_id", "project_id"]},
     "issue_priority": {"required_fields": ["organization_id"]},
     "issue_replay_inline_onboarding": {"required_fields": ["organization_id", "project_id"]},