fix: fix NFT balance in send flow

[sahar-fehri]

Description

Fixes balance for NFTs in send flow.

Related issues

Fixes: #28298

Manual testing steps

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Screenshots/Recordings

Before

Please see video in issue 🙏

After

Screen.Recording.2025-03-24.at.12.40.35.mov

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[sahar-fehri]

Using addHexPrefix is what triggered the bug in the NFT send flow.
When deploying a tokenId 1 and 2 with amount 10 and 15
using addHexPrefix resulted in the balance being 0x10 and 0x15.
In the AssetBalanceText component we will calculate the number of tokens of nfts
const numberOfTokens = hexToDecimal(asset.balance || '0x0');
Which results in numberOfTokens being 16 and 21 instead of 10 and 15

[metamaskbot]

Builds ready [862b93d]

• builds: chrome, firefox
• builds (flask): chrome, firefox
• builds (MMI): chrome
• builds (test): chrome, firefox
• builds (test-flask): chrome, firefox
• build viz: Build System
• mv3: Bundle Size Stats
• mv2: E2e Actions Stats
• storybook: Storybook
• typescript migration: Dashboard
• all artifacts
• bundle viz:

  • background: 0, 1, 2, 3, 4, 5, 6, 7, 8
  • common: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13
  • ui: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12
  • content-script: 0
  • offscreen: 0

Page Load Metrics (2829 ± 360 ms)

Platform	Page	Metric	Min (ms)	Max (ms)	Average (ms)	StandardDeviation (ms)	MarginOfError (ms)
Chrome	Home	firstPaint	380	4291	2416	856	411
		domContentLoaded	1812	3980	2324	470	226
		load	1869	4609	2829	751	360
		domInteractive	28	152	50	31	15
		backgroundConnect	87	1567	515	424	204
		firstReactRender	20	1112	162	227	109
		getState	18	1048	214	234	112
		initialActions	0	21	1	5	2
		loadScripts	1311	2483	1619	252	121
		setupStore	11	1895	199	407	195
		uiStartup	2564	20359	6299	4588	2203

Bundle size diffs [🚨 Warning! Bundle size has increased!]

• background: 0 Bytes (0.00%)
• ui: 0 Bytes (0.00%)
• common: 142 Bytes (0.00%)