[Connect SDK] Initial API shape

[simond-stripe]

Summary

Add the initial API shape, mirroring much of iOS here: https://docs.google.com/document/d/195BaU6k2J-2CAs9anNE6e4OlZO34N-e2HTYc6pacpTw/edit#heading=h.dqbdoct8funi

Note that this is still hidden behind private beta flag and is scoped to the library.

Motivation

This PR builds out the scaffold for the Connect SDK, which allows us to implement the methods in parallel from there (and test incrementally as we do it).

Testing

• Added tests
• Modified tests
• Manually verified

[github-actions]

Diffuse output:

OLD: identity-example-release-base.apk (signature: V1, V2)
NEW: identity-example-release-pr.apk (signature: V1, V2)

          │          compressed          │         uncompressed         
          ├───────────┬───────────┬──────┼───────────┬───────────┬──────
 APK      │ old       │ new       │ diff │ old       │ new       │ diff 
──────────┼───────────┼───────────┼──────┼───────────┼───────────┼──────
      dex │   1.9 MiB │   1.9 MiB │  0 B │     4 MiB │     4 MiB │  0 B 
     arsc │     1 MiB │     1 MiB │  0 B │     1 MiB │     1 MiB │  0 B 
 manifest │   2.3 KiB │   2.3 KiB │  0 B │     8 KiB │     8 KiB │  0 B 
      res │ 301.5 KiB │ 301.5 KiB │  0 B │   455 KiB │   455 KiB │  0 B 
   native │   6.2 MiB │   6.2 MiB │  0 B │  15.8 MiB │  15.8 MiB │  0 B 
    asset │   6.8 KiB │   6.8 KiB │  0 B │   6.6 KiB │   6.6 KiB │  0 B 
    other │  85.5 KiB │  85.5 KiB │  0 B │ 158.7 KiB │ 158.7 KiB │  0 B 
──────────┼───────────┼───────────┼──────┼───────────┼───────────┼──────
    total │   9.5 MiB │   9.5 MiB │  0 B │  21.4 MiB │  21.4 MiB │  0 B 

 DEX     │ old   │ new   │ diff      
─────────┼───────┼───────┼───────────
   files │     1 │     1 │ 0         
 strings │ 20269 │ 20269 │ 0 (+0 -0) 
   types │  6106 │  6106 │ 0 (+0 -0) 
 classes │  4913 │  4913 │ 0 (+0 -0) 
 methods │ 29561 │ 29561 │ 0 (+0 -0) 
  fields │ 17371 │ 17371 │ 0 (+0 -0) 

 ARSC    │ old  │ new  │ diff 
─────────┼──────┼──────┼──────
 configs │  164 │  164 │  0   
 entries │ 3608 │ 3608 │  0

APK

   compressed    │   uncompressed   │                                           
──────────┬──────┼───────────┬──────┤                                           
 size     │ diff │ size      │ diff │ path                                      
──────────┼──────┼───────────┼──────┼───────────────────────────────────────────
 25.1 KiB │ +3 B │  62.5 KiB │  0 B │ ∆ META-INF/MANIFEST.MF                    
 28.3 KiB │ -2 B │  62.6 KiB │  0 B │ ∆ META-INF/CERT.SF                        
    271 B │ -1 B │     120 B │  0 B │ ∆ META-INF/version-control-info.textproto 
──────────┼──────┼───────────┼──────┼───────────────────────────────────────────
 53.7 KiB │  0 B │ 125.2 KiB │  0 B │ (total)