IPFS config: lower the ConnMgr.HighWater and LowWater limits

[lidel]

The default (ConnMgr.LowWater=600 and HighWater=900) are bit too high for desktop use. Those are aimed at server use.
Desktop users may experience issues if they are connected to a LAN managed by inexpensive consumer routers (some models crash when 1k of connections is passed).

IPFS Desktop has been running for years with (LowWater=50 and HighWater=300)
and I suggest Brave sets the same values after ipfs init as it decreases the risk of crashing LAN for users.

cc @bbondy @yrliou

[LaurenWags]

Will need a new build to test on 1.19.x, QA/Blocked for now.

[LaurenWags]

Verified using

Brave | 1.19.84 Chromium: 88.0.4324.87 (Official Build) (x86_64)
-- | --
Revision | dd01ff8f58c65af81127ad5c105c79d5b571d8f3-refs/branch-heads/4324@{#1702}
OS | macOS Version 10.15.7 (Build 19H15)

Verified test plan from brave/brave-core#7577 (comment)

Using a clean profile, visited ipfs://QmbWqxBEKC3P8tqsKc98xmWNzrzDtRLMiMPL8wBuTGsMnR to trigger IPFS infobar.
Installed IPFS from infobar.
Opened ~/Library/Application Support/BraveSoftware/Brave-Browser/brave_ipfs/config file.

Confirmed updated config values of LowWater=50 and HighWater=300.

Spot checked able to load ipfs:// and ipns:// URLs without issue.

---

Verification passed on

Brave | 1.19.84 Chromium: 88.0.4324.87 (Official Build) (64-bit)
-- | --
Revision | dd01ff8f58c65af81127ad5c105c79d5b571d8f3-refs/branch-heads/4324@{#1702}
OS | Windows 10 OS Version 2004 (Build 19041.685)

Verified test plan from brave/brave-core#7577 (comment)

Using a clean profile, visited ipfs://QmbWqxBEKC3P8tqsKc98xmWNzrzDtRLMiMPL8wBuTGsMnR to trigger IPFS infobar.
Installed IPFS from infobar.
Opened ...AppData\Local\BraveSoftware\Brave-Browser\User Data\brave_ipfs/config file.

Confirmed updated config values of LowWater=50 and HighWater=300.

---

Verification passed on

Brave	1.19.84 Chromium: 88.0.4324.87 (Official Build) (64-bit)
Revision	dd01ff8f58c65af81127ad5c105c79d5b571d8f3-refs/branch-heads/4324@{#1702}
OS	Ubuntu 18.04 LTS

Verified test plan from brave/brave-core#7577