Replace assets for avatar placeholder on Android

build/android/lint/suppressions.xml

 <?xml version="1.0" encoding="utf-8"?>
 <lint>
   <!--
 STOP! It looks like you want to suppress some lint errors:
 - Have you tried identifing the offending patch?
   Ask the author for a fix and/or revert the patch.
 - It is preferred to add suppressions in the code instead of
   sweeping it under the rug here. See:
 
     http://developer.android.com/tools/debugging/improving-w-lint.html
@@ skipping 178 matching lines @@
   </issue>
   <issue id="NewApi">
     <ignore regexp="Attribute `paddingStart` referenced here can result in a crash on some specific devices older than API 17"/>
     <ignore regexp="chrome/android/java/res/drawable/downloads_big.xml"/>
     <ignore regexp="chrome/android/java/res/drawable/ic_bluetooth_connected.xml"/>
     <ignore regexp="chrome/android/java/res/drawable/ic_signal_cellular_0_bar.xml" />
     <ignore regexp="chrome/android/java/res/drawable/ic_signal_cellular_1_bar.xml" />
     <ignore regexp="chrome/android/java/res/drawable/ic_signal_cellular_2_bar.xml" />
     <ignore regexp="chrome/android/java/res/drawable/ic_signal_cellular_3_bar.xml" />
     <ignore regexp="chrome/android/java/res/drawable/ic_signal_cellular_4_bar.xml" />
+    <ignore regexp="chrome/android/java/res/drawable/logo_avatar_anonymous.xml"/>

[Theresa, 2017/06/01 23:22:15]

optional nit: Instead of adding an ingnore here, you can add
tools:targetApi="21" to the <vector> in the XML file. I don't know that we have
an established pattern (some vectors use tools: some add a rule here), but my
preference is tools:.

[bsazonov, 2017/06/02 13:17:20]

Didn't know about this option, thanks! I totally agree that this is way better
than ignoring it suppressions.xml.

     <ignore regexp="chrome/android/java/res/values-v17/styles.xml"/>
     <ignore regexp="chromecast/internal"/>
     <ignore regexp="com/android/tv"/>
     <ignore regexp="com/android/webview/chromium/ServiceWorkerControllerAdapter.class"/>
     <ignore regexp="com/android/webview/chromium/ServiceWorkerSettingsAdapter.class"/>
     <ignore regexp="com/android/webview/chromium/WebViewChromium.class"/>
     <ignore regexp="com/android/webview/chromium/WebViewChromiumFactoryProvider.class"/>
     <ignore regexp="com/chrome/cloud/experimental/airspeed/BenchmarksTest.class"/>
     <ignore regexp="com/google/android/apps/cast"/>
     <ignore regexp="com/google/android/apps/mediashell"/>
@@ skipping 253 matching lines @@
     <ignore regexp="chrome/android/javatests"/>
     <ignore regexp="/test/"/>
   </issue>
   <issue id="WrongCall" severity="ignore"/>
   <issue id="WrongConstant">
     <ignore regexp="chrome/android/java/src/org/chromium/chrome/browser/SSLClientCertificateRequest.java"/>
     <ignore regexp="chrome/android/java/src/org/chromium/chrome/browser/payments/ui/EditorDialog.java"/>
     <ignore regexp="chrome/android/java/src/org/chromium/chrome/browser/signin/SigninAndSyncView.java"/>
   </issue>
 </lint>