[Desktop] NTP Estimated bandwidth saved stat is not shown on clean install

[btlechowski]

Follow up to #8969

Steps to Reproduce

1. Clean install
2. Open new tab

Important: after loading 1 page, the stat is shown

Actual result:

NTP Estimated bandwidth saved stat is not shown on clean install

Expected result:

NTP Estimated bandwidth saved stat is shown on clean install

Reproduces how often:

100% repro rate

Brave version (brave://version info)

Brave	1.10.74 Chromium: 81.0.4044.138 (Official Build) dev (64-bit)
Revision	8c6c7ba89cc9453625af54f11fd83179e23450fa-refs/branch-heads/4044@{#999}
OS	Ubuntu 18.04 LTS

Brave	1.11.31 Chromium: 83.0.4103.61 (Official Build) nightly (64-bit)
Revision	94f915a8d7c408b09cc7352161ad592299f384d2-refs/branch-heads/4103@{#561}
OS	Windows 7 Service Pack 1 (Build 7601.24544)

cc @brave/legacy_qa @rebron @AndriusA @karenkliu

[rebron]

cc: @AndriusA Can you take a look?

[AndriusA]

will do, there's a simple explicit condition that hides the metric if it is zero, will remove it

[LaurenWags]

Verified passed with

Brave | 1.12.92 Chromium: 84.0.4147.89 (Official Build) dev (64-bit)
-- | --
Revision | 19abfe7bcba9318a0b2a6bc6634a67fc834aa592-refs/branch-heads/4147@{#852}
OS | macOS Version 10.14.6 (Build 18G3020)

• Verified STR from description

---

Verification passed on

Brave | 1.12.94 Chromium: 84.0.4147.89 (Official Build) dev (64-bit)
-- | --
Revision | 19abfe7bcba9318a0b2a6bc6634a67fc834aa592-refs/branch-heads/4147@{#852}
OS | Windows 10 OS Version 1903 (Build 18362.959)

• Verified STR from the description
  

---

Verification passed on

Brave	1.12.99 Chromium: 84.0.4147.89 (Official Build) dev (64-bit)
Revision	19abfe7bcba9318a0b2a6bc6634a67fc834aa592-refs/branch-heads/4147@{#852}
OS	Ubuntu 18.04 LTS

• Verified test plan from the description