Rework to use KUKSA.val databroker gRPC API

Rework to move from the WebSocket API with the older KUKSA.val
server to the gRPC "VAL" API of the databroker.

Changes include:
- All VISS WebSocket API code has been removed, and the signal
  providers replumbed to be driven by a new VssClient class with
  a dashboard-specific child class to hold all the gRPC API
  handling.
- The generated code for the VAL API and its dependencies has
  been checked in under lib/generated, as there still does not
  seem to be a good way to generate it during the Flutter build.
- The configuration file is now expected to be "dashboard.yaml"
  instead of "dashboard.yaml".  The authorization token
  field name has been renamed to "authorization", and there are
  new "use-tls" and "ca-certificate" configuration fields.  TLS
  is disabled by default for now, and the default CA certificate
  is /etc/kuksa.val/CA.pem.
- Bumped minimum SDK version to 2.18 in pubspec.yaml to enable
  "super" keyword support.  This matches what the version was set
  to in flutter-homescreen.
- Removed .dart_tool generated output that had been checked in,
  and added .gitignore file from flutter-homescreen so that things
  will hopefully stay clean in the future.

Bug-AGL: SPEC-4762

Signed-off-by: Scott Murray <scott.murray@konsulko.com>
Change-Id: Ie23091b759458b5a131bc2d85e62925238839166

1 files changed, 21 insertions, 0 deletions

diff --git a/lib/generated/google/protobuf/timestamp.pbjson.dart b/lib/generated/google/protobuf/timestamp.pbjson.dart
new file mode 100644
index 0000000..421f785
--- /dev/null
+++ b/lib/generated/google/protobuf/timestamp.pbjson.dart
@@ -0,0 +1,21 @@
+///
+//  Generated code. Do not modify.
+//  source: google/protobuf/timestamp.proto
+//
+// @dart = 2.12
+// ignore_for_file: annotate_overrides,camel_case_types,constant_identifier_names,deprecated_member_use_from_same_package,directives_ordering,library_prefixes,non_constant_identifier_names,prefer_final_fields,return_of_invalid_type,unnecessary_const,unnecessary_import,unnecessary_this,unused_import,unused_shown_name
+
+import 'dart:core' as $core;
+import 'dart:convert' as $convert;
+import 'dart:typed_data' as $typed_data;
+@$core.Deprecated('Use timestampDescriptor instead')
+const Timestamp$json = const {
+  '1': 'Timestamp',
+  '2': const [
+    const {'1': 'seconds', '3': 1, '4': 1, '5': 3, '10': 'seconds'},
+    const {'1': 'nanos', '3': 2, '4': 1, '5': 5, '10': 'nanos'},
+  ],
+};
+
+/// Descriptor for `Timestamp`. Decode as a `google.protobuf.DescriptorProto`.
+final $typed_data.Uint8List timestampDescriptor = $convert.base64Decode('CglUaW1lc3RhbXASGAoHc2Vjb25kcxgBIAEoA1IHc2Vjb25kcxIUCgVuYW5vcxgCIAEoBVIFbmFub3M=');