Fix Forms when there is only one payment method available

[tjclawson-stripe]

Summary

Update PaymentElement and VerticalModeFormUI to show VerticalModeFormHeaderUI if there is only one non card payment method.

Motivation

Fix empty form display

• If wallet is available and there is one supported payment method
  • If PM is card > Do not show header as divider text displays "Or pay with card"
  • If PM is not card > Show header
• If wallet is not available and there is only one supported payment method
  • If PM is card > Show title
  • If PM is not card > Show header

Testing

• Added tests
• Modified tests
• Manually verified

Screen.Recording.2025-11-09.at.7.50.39.PM.mov

[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 │   2.1 MiB │   2.1 MiB │  0 B │   4.3 MiB │   4.3 MiB │  0 B 
     arsc │   1.1 MiB │   1.1 MiB │  0 B │   1.1 MiB │   1.1 MiB │  0 B 
 manifest │   2.3 KiB │   2.3 KiB │  0 B │     8 KiB │     8 KiB │  0 B 
      res │ 303.5 KiB │ 303.5 KiB │  0 B │ 457.7 KiB │ 457.7 KiB │  0 B 
   native │   7.9 MiB │   7.9 MiB │  0 B │  19.3 MiB │  19.3 MiB │  0 B 
    asset │   7.7 KiB │   7.7 KiB │  0 B │   7.4 KiB │   7.4 KiB │  0 B 
    other │  95.6 KiB │  95.6 KiB │ +4 B │ 183.6 KiB │ 183.6 KiB │  0 B 
──────────┼───────────┼───────────┼──────┼───────────┼───────────┼──────
    total │  11.5 MiB │  11.5 MiB │ +4 B │  25.4 MiB │  25.4 MiB │  0 B 

 DEX     │ old   │ new   │ diff      
─────────┼───────┼───────┼───────────
   files │     1 │     1 │ 0         
 strings │ 20719 │ 20719 │ 0 (+0 -0) 
   types │  6512 │  6512 │ 0 (+0 -0) 
 classes │  5276 │  5276 │ 0 (+0 -0) 
 methods │ 31556 │ 31556 │ 0 (+0 -0) 
  fields │ 18288 │ 18288 │ 0 (+0 -0) 

 ARSC    │ old  │ new  │ diff 
─────────┼──────┼──────┼──────
 configs │  163 │  163 │  0   
 entries │ 3667 │ 3667 │  0

APK

   compressed    │   uncompressed   │                                           
──────────┬──────┼───────────┬──────┤                                           
 size     │ diff │ size      │ diff │ path                                      
──────────┼──────┼───────────┼──────┼───────────────────────────────────────────
 29.2 KiB │ +7 B │  64.6 KiB │  0 B │ ∆ META-INF/CERT.SF                        
    270 B │ -2 B │     120 B │  0 B │ ∆ META-INF/version-control-info.textproto 
 25.9 KiB │ -1 B │  64.6 KiB │  0 B │ ∆ META-INF/MANIFEST.MF                    
──────────┼──────┼───────────┼──────┼───────────────────────────────────────────
 55.4 KiB │ +4 B │ 129.3 KiB │  0 B │ (total)

[amk-stripe]

should we also have screenshot tests for this? The tests you added seem like they would catch a regression but if they fail, it's a little hard to understand the impact. Vs in a screenshot test, it would be pretty obvious

[amk-stripe]

Suggested change

	return if (selectedCode == PaymentMethod.Type.Card.code) !showsWalletHeader else true
	return (selectedCode != PaymentMethod.Type.Card.code) || !showsWalletHeader

[amk-stripe]

a bit easier to read and should return the same values