Update packages files in analyzer_cli to package_config.json format.

We need this for https://dart-review.googlesource.com/c/sdk/+/238181

Bug: https://github.com/dart-lang/sdk/issues/48272
Change-Id: I8dffd0d5bb9bc635dd60a690466b89ace25b9a71
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/244283
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Konstantin Shcheglov <scheglov@google.com>

pkg/analyzer_cli/test/data/embedder_client/_packages

@@ -1 +1,10 @@
-sky_engine:../sky_engine/lib/
+{
+  "configVersion": 2,
+  "packages": [
+    {
+      "name": "sky_engine",
+      "rootUri": "../sky_engine",
+      "packageUri": "lib/"
+    }
+  ]
+}

pkg/analyzer_cli/test/data/flutter_analysis_options/packagelist

@@ -1,2 +1,15 @@
-flutter:somepkgs/flutter/lib/
-meta:somepkgs/meta/lib/
+{
+  "configVersion": 2,
+  "packages": [
+    {
+      "name": "flutter",
+      "rootUri": "somepkgs/flutter/",
+      "packageUri": "lib/"
+    },
+    {
+      "name": "meta",
+      "rootUri": "somepkgs/meta/",
+      "packageUri": "lib/"
+    }
+  ]
+}

pkg/analyzer_cli/test/data/options_include_directive_tests_project/_packages

@@ -1,3 +1,15 @@
-# Generated by pub on 2016-11-30 13:02:00.280796.
-foo:pkg/foo/lib/
-options_include_directive_tests_project:lib/
+{
+  "configVersion": 2,
+  "packages": [
+    {
+      "name": "foo",
+      "rootUri": "pkg/foo/",
+      "packageUri": "lib/"
+    },
+    {
+      "name": "options_include_directive_tests_project",
+      "rootUri": ".",
+      "packageUri": "lib/"
+    }
+  ]
+}

pkg/analyzer_cli/test/data/package_prefix/packagelist

@@ -1,2 +1,13 @@
-bar:pkg/bar/
-foo:pkg/foo/
+{
+  "configVersion": 2,
+  "packages": [
+    {
+      "name": "foo",
+      "rootUri": "pkg/foo/"
+    },
+    {
+      "name": "bar",
+      "rootUri": "pkg/bar/"
+    }
+  ]
+}