Remove target monochrome_static_initializers from android-marshmallow-x86-fyi-rel

It looks like this target does not apply to x86.
See https://cs.chromium.org/chromium/src/chrome/android/BUILD.gn?rcl=833be61e91e914e4e84dd2f2a86d35433746b8c8&l=2160 and https://cs.chromium.org/chromium/src/chrome/android/static_initializers.gni?rcl=909cd47e9565dc8cca8b1ca5e7647203b325c851&l=15

Bug: 997376
Change-Id: Id2f6c5dc9112a058bb6ef3d85569faeeafcd04ae
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1790431Reviewed-by: Ben Pastene <bpastene@chromium.org>
Reviewed-by: John Budorick <jbudorick@chromium.org>
Commit-Queue: Haiyang Pan <hypan@google.com>
Cr-Commit-Position: refs/heads/master@{#694872}

testing/buildbot/chromium.android.fyi.json

@@ -413,9 +413,6 @@
     ]
   },
   "android-marshmallow-x86-fyi-rel": {
-    "additional_compile_targets": [
-      "monochrome_static_initializers"
-    ],
     "gtest_tests": [
       {
         "args": [

testing/buildbot/waterfalls.pyl

@@ -678,9 +678,6 @@
           'x86-64',
         ],
         'os_type': 'android',
-        'additional_compile_targets': [
-          'monochrome_static_initializers',
-        ],
         'test_suites': {
           'gtest_tests': 'android_lollipop_marshmallow_gtests',
           'isolated_scripts': 'marshmallow_isolated_scripts',