feat(fdc): Data Connect Dart SDK init #5389

Job	Run time
android (tests)	2m 1s
android (packages/cloud_firestore/cloud_firestore/example)	2m 2s
ios (tests)	2m 15s
macos (tests)	2m 12s
ios (packages/cloud_firestore/cloud_firestore/example)	2m 15s
macos (packages/cloud_firestore/cloud_firestore/example)	2m 13s
web (tests)	2m 16s
web (packages/cloud_firestore/cloud_firestore/example)	2m 19s
web-wasm (tests)	2m 18s
windows	1m 58s
web-wasm (packages/cloud_firestore/cloud_firestore/example)	2m 29s
windows-firestore	1m 57s
	26m 15s

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