Bug 1892884 - Run GeckoSessionTestRuleTest#contentCrashIgnored with fission. r=geckoview-reviewers,calu

This test can run with fission if not isolation process, so let's turn on it.

Differential Revision: https://phabricator.services.mozilla.com/D208310

mobile/android/geckoview/src/androidTest/java/org/mozilla/geckoview/test/GeckoSessionTestRuleTest.kt

@@ -2029,9 +2029,6 @@ class GeckoSessionTestRuleTest : BaseSessionTest(noErrorCollector = true) {
     @IgnoreCrash
     @Test
     fun contentCrashIgnored() {
-        // TODO: Bug 1673953
-        assumeThat(sessionRule.env.isFission, equalTo(false))
-
         // TODO: bug 1710940
         assumeThat(sessionRule.env.isIsolatedProcess, equalTo(false))