Telemetry: Disable loading.desktop.network_service/AirBnB,Kenh14,Taobao

The following tests are failing on Mojo Linux Perf:
* loading.desktop.network_service/AirBnB_cold
* loading.desktop.network_service/AirBnB_warm
* loading.desktop.network_service/Kenh14_cold
* loading.desktop.network_service/Kenh14_warm
* loading.desktop.network_service/Taobao_cold
* loading.desktop.network_service/Taobao_warm

See bug for deailed reports.

This patch also cleaned up platform filters (only have Linux bot).

(TBR since it's Mojo Linux Perf bot only)
TBR=kouhei@chromium.org

Bug: 853835
Change-Id: Idaf3487bd8933b93cd8f4e93c81645dcc8712ade
Reviewed-on: https://chromium-review.googlesource.com/1105023Reviewed-by: Chong Zhang <chongz@chromium.org>
Commit-Queue: Chong Zhang <chongz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#568210}

tools/perf/expectations.config

@@ -497,9 +497,13 @@ crbug.com/814012 [ Win ] wasm/AsmJsZenGarden [ Skip ]
 
 ##### Perf FYI benchmarks go after here #####
 # Benchmark: loading.desktop.network_service
-crbug.com/723783 [ Win ] loading.desktop.network_service/Orange_cold [ Skip ]
-crbug.com/723783 [ Win ] loading.desktop.network_service/Orange_warm [ Skip ]
 crbug.com/752611 [ Linux ] loading.desktop.network_service/uol.com.br_cold [ Skip ]
 crbug.com/752611 [ Linux ] loading.desktop.network_service/uol.com.br_warm [ Skip ]
-crbug.com/851171 [ All ] loading.desktop.network_service/Elmundo_cold [ Skip ]
-crbug.com/851171 [ All ] loading.desktop.network_service/Elmundo_warm [ Skip ]
+crbug.com/851171 [ Linux ] loading.desktop.network_service/Elmundo_cold [ Skip ]
+crbug.com/851171 [ Linux ] loading.desktop.network_service/Elmundo_warm [ Skip ]
+crbug.com/853835 [ Linux ] loading.desktop.network_service/AirBnB_cold [ Skip ]
+crbug.com/853835 [ Linux ] loading.desktop.network_service/AirBnB_warm [ Skip ]
+crbug.com/853835 [ Linux ] loading.desktop.network_service/Kenh14_cold [ Skip ]
+crbug.com/853835 [ Linux ] loading.desktop.network_service/Kenh14_warm [ Skip ]
+crbug.com/853835 [ Linux ] loading.desktop.network_service/Taobao_cold [ Skip ]
+crbug.com/853835 [ Linux ] loading.desktop.network_service/Taobao_warm [ Skip ]