Update gyp files to depend on metrics' standalone ebuild.

Metrics is now installed by chromeos-base/metrics.
Platform2 packages should depend on it through the variable:deps mechanism
instead of depending directly on metrics' gyp file.

BUG=chromium:387923
TEST=Build platform2. metrics gets installed and the tests succeed.
TEST=Trybot run on daisy-release, lumpy-incremental-paladin, link-release,
  duck-release, x86-mario-release.

CQ-DEPEND=CL:205312

Change-Id: I07607d5fa574ce3c273fc4189590453edbee2aa4
Reviewed-on: https://chromium-review.googlesource.com/205299
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Tested-by: Bertrand Simonnet <bsimonnet@chromium.org>
Commit-Queue: Bertrand Simonnet <bsimonnet@chromium.org>

crash_reporter/crash-reporter.gyp

@@ -52,11 +52,11 @@
         'deps': [
           'dbus-1',
           'dbus-glib-1',
+          'libmetrics-<(libbase_ver)',
         ],
       },
       'dependencies': [
         'libcrash',
-        '../metrics/libmetrics-<(libbase_ver).gyp:libmetrics-<(libbase_ver)',
       ],
       'sources': [
         'crash_reporter.cc',
@@ -81,15 +81,15 @@
       'type': 'executable',
       'variables': {
         'lexer_out_dir': 'crash-reporter',
+        'deps': [
+          'libmetrics-<(libbase_ver)',
+        ],
       },
       'link_settings': {
         'libraries': [
           '-lfl',
         ],
       },
-      'dependencies': [
-        '../metrics/libmetrics-<(libbase_ver).gyp:libmetrics-<(libbase_ver)',
-      ],
       'sources': [
         'warn_collector.l',
       ],