Inspector Preferences doesn't load on start-paused

[CoderDake]

This has something to do with us calling our init when connection is available, but not being respectful of isPaused

[ERROR:flutter/runtime/dart_vm_initializer.cc(41)] Unhandled Exception: 'package:devtools_app/src/shared/preferences.dart': Failed assertion: line 273 pos 12: '_mainScriptDir != null': is not true.
package:devtools_app/…/shared/preferences.dart:273
#2      InspectorPreferencesController._customPubRootStorageId
package:devtools_app/…/shared/preferences.dart:273
#3      InspectorPreferencesController.loadCustomPubRootDirectories.<anonymous closure>
package:devtools_app/…/shared/preferences.dart:283
#4      InspectorPreferencesController._customPubRootDirectoryBusyTracker
package:devtools_app/…/shared/preferences.dart:301
#5      InspectorPreferencesController.loadCustomPubRootDirectories
package:devtools_app/…/shared/preferences.dart:281
#4      InspectorPreferencesController.addPubRootDirectories.<anonymous closure>
package:devtools_app/…/shared/preferences.dart:233
#5      InspectorPreferencesController._customPubRootDirectoryBusyTracker
package:devtools_app/…/shared/preferences.dart:301
#6      InspectorPreferencesController.addPubRootDirectories
package:devtools_app/…/shared/preferences.dart:229
#7      InspectorPreferencesController.loadCustomPubRootDirectories.<anonymous closure>
package:devtools_app/…/shared/preferences.dart:286
#8      InspectorPreferencesController._customPubRootDirectoryBusyTracker
package:devtools_app/…/shared/preferences.dart:301
#9      InspectorPreferencesController.loadCustomPubRootDirectories
package:devtools_app/…/shared/preferences.dart:281
#10     InspectorPreferencesController._handleConnectionToNewService