fix(ttfd): measurements should only be added for successful ttfd

[buenaflor]

📜 Description

Currently measurements are also added even for unsuccessful ttfd spans

💡 Motivation and Context

Might be the fix for #2191

💚 How did you test it?

Unit test

📝 Checklist

• I reviewed submitted code
• I added tests to verify changes
• No new PII added or SDK only sends newly added PII if sendDefaultPii is enabled
• I updated the docs if needed
• All tests passing
• No breaking changes

🔮 Next steps

[codecov]

Codecov Report

Attention: Patch coverage is 87.50000% with 1 line in your changes missing coverage. Please review.

Project coverage is 85.13%. Comparing base (f3a18f2) to head (ed28c79).
Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
...b/src/navigation/time_to_full_display_tracker.dart	87.50%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2348      +/-   ##
==========================================
+ Coverage   84.81%   85.13%   +0.32%     
==========================================
  Files         253       79     -174     
  Lines        9054     2785    -6269     
==========================================
- Hits         7679     2371    -5308     
+ Misses       1375      414     -961     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[github-actions]

Android Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	451.80 ms	492.94 ms	41.14 ms
Size	6.49 MiB	7.57 MiB	1.08 MiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
7273303	415.33 ms	491.51 ms	76.18 ms
a609134	350.12 ms	404.12 ms	54.00 ms
21d4150	379.31 ms	449.23 ms	69.93 ms
78eeed5	298.35 ms	361.63 ms	63.28 ms
5f443de	412.30 ms	491.67 ms	79.37 ms
50bdfad	395.22 ms	461.21 ms	65.98 ms
9555112	448.81 ms	488.89 ms	40.08 ms
c57d3b7	413.56 ms	508.80 ms	95.24 ms
d783424	302.08 ms	368.10 ms	66.02 ms
d189e01	328.67 ms	397.12 ms	68.45 ms

App size

Revision	Plain	With Sentry	Diff
7273303	6.34 MiB	7.29 MiB	970.36 KiB
a609134	5.94 MiB	6.95 MiB	1.01 MiB
21d4150	5.94 MiB	6.97 MiB	1.03 MiB
78eeed5	6.16 MiB	7.14 MiB	1009.97 KiB
5f443de	6.35 MiB	7.34 MiB	1008.00 KiB
50bdfad	6.33 MiB	7.30 MiB	987.47 KiB
9555112	6.52 MiB	7.59 MiB	1.06 MiB
c57d3b7	6.33 MiB	7.30 MiB	992.08 KiB
d783424	6.16 MiB	7.14 MiB	1007.48 KiB
d189e01	6.16 MiB	7.14 MiB	1009.90 KiB

[github-actions]

iOS Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	1253.23 ms	1271.72 ms	18.49 ms
Size	8.38 MiB	9.75 MiB	1.37 MiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
333903e	1251.15 ms	1270.21 ms	19.06 ms
d53c6fa	1254.86 ms	1270.83 ms	15.97 ms
b66cc27	1249.64 ms	1275.57 ms	25.94 ms
bf8d36c	1238.33 ms	1258.71 ms	20.38 ms
ffae3e3	1215.82 ms	1238.49 ms	22.67 ms
6fedcab	1242.33 ms	1269.66 ms	27.33 ms
ba9c106	1241.76 ms	1265.15 ms	23.40 ms
bc29768	1247.25 ms	1268.63 ms	21.38 ms
a4c4f8c	1217.77 ms	1245.88 ms	28.11 ms
3e5078c	1239.73 ms	1248.69 ms	8.96 ms

App size

Revision	Plain	With Sentry	Diff
333903e	8.10 MiB	9.16 MiB	1.06 MiB
d53c6fa	8.29 MiB	9.39 MiB	1.10 MiB
b66cc27	8.38 MiB	9.74 MiB	1.36 MiB
bf8d36c	8.38 MiB	9.74 MiB	1.36 MiB
ffae3e3	8.28 MiB	9.33 MiB	1.05 MiB
6fedcab	8.32 MiB	9.50 MiB	1.18 MiB
ba9c106	8.32 MiB	9.38 MiB	1.06 MiB
bc29768	8.32 MiB	9.38 MiB	1.05 MiB
a4c4f8c	8.38 MiB	9.74 MiB	1.36 MiB
3e5078c	8.28 MiB	9.34 MiB	1.06 MiB

[buenaflor]

cc @stefanosiano pls take a look

[stefanosiano]

nice!