fix: use PORTFOLIO_VIEW flag to determine token list polling

[bergeron]

Description

Updates the token list hook to only poll across chains when PORTFOLIO_VIEW is set.

Related issues

Manual testing steps

1. With PORTFOLIO_VIEW=1, requests should go to the token api across all chains.
2. Without PORTFOLIO_VIEW=1, requests should go to the token api on the current chain.

Screenshots/Recordings

Before

After

Pre-merge author checklist

• I've followed MetaMask Contributor Docs and MetaMask Extension Coding Standards.
• I've completed the PR template to the best of my ability
• I’ve included tests if applicable
• I’ve documented my code using JSDoc format if applicable
• I’ve applied the right labels on the PR (see labeling guidelines). Not required for external contributors.

Pre-merge reviewer checklist

• I've manually tested the PR (e.g. pull and build branch, run the app, test code being changed).
• I confirm that this PR addresses all acceptance criteria described in the ticket it closes and includes the necessary testing evidence such as recordings and or screenshots.

[github-actions]

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[bergeron]

fixing e2e

[metamaskbot]

Builds ready [5e9487a]

• builds: chrome, firefox
• builds (beta): chrome
• builds (flask): chrome, firefox
• builds (MMI): chrome, firefox
• builds (test): chrome, firefox
• builds (test-flask): chrome, firefox
• build viz: Build System
• mv3: Background Module Init Stats
• mv3: UI Init Stats
• mv3: Module Load Stats
• mv3: Bundle Size Stats
• mv2: E2e Actions Stats
• code coverage: Report
• storybook: Storybook
• typescript migration: Dashboard
• all artifacts
• bundle viz:

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

Page Load Metrics (1853 ± 47 ms)

Platform	Page	Metric	Min (ms)	Max (ms)	Average (ms)	StandardDeviation (ms)	MarginOfError (ms)
Chrome	Home	firstPaint	352	2116	1784	343	165
		domContentLoaded	1610	1998	1814	92	44
		load	1659	2064	1853	98	47
		domInteractive	16	209	54	40	19
		backgroundConnect	7	85	43	21	10
		firstReactRender	64	381	127	72	35
		getState	4	68	18	18	9
		initialActions	0	1	0	0	0
		loadScripts	1170	1528	1339	86	41
		setupStore	6	87	19	24	11
		uiStartup	1953	2444	2115	123	59

Bundle size diffs

• background: 0 Bytes (0.00%)
• ui: 34 Bytes (0.00%)
• common: 0 Bytes (0.00%)