Update script to run R8/D8 on prebuild applications

Rename tools/run_r8_on_app.py to tools/run_on_app.py and add the --compiler
option to support both R8 and D8.

Cleanup of tools/gmail_data.py.

Change-Id: Ic258f563c228bdae717cd4213678f2dbf13b8c13
diff --git a/tools/gmail_data.py b/tools/gmail_data.py
index ab1e6b4..d09a3e8 100644
--- a/tools/gmail_data.py
+++ b/tools/gmail_data.py
@@ -12,8 +12,7 @@
 V170604_16_BASE = os.path.join(BASE, 'gmail_android_170604.16')
 V170604_16_PREFIX = os.path.join(V170604_16_BASE, 'Gmail_release_unstripped')
 
-# NOTE: we always use android.jar for SDK v25, later we might want to revise it
-#       to use proper android.jar version for each of youtube version separately.
+# NOTE: We always use android.jar for SDK v25 for now.
 ANDROID_JAR = os.path.join(THIRD_PARTY, 'android_jar', 'lib-v25', 'android.jar')
 
 VERSIONS = {
@@ -21,13 +20,12 @@
     'dex' : {
       'inputs': [os.path.join(V170604_16_BASE, 'Gmail_release_unsigned.apk')],
       'pgmap': '%s_proguard.map' % V170604_16_PREFIX,
-      'libraries' : [ANDROID_JAR, '/usr/local/buildtools/java/jdk-64/jre/lib/rt.jar'],
+      'libraries' : [ANDROID_JAR],
       'r8-flags': '--ignore-missing-classes',
     },
     'deploy' : {
       'inputs': ['%s_deploy.jar' % V170604_16_PREFIX],
-      'pgconf': ['%s_proguard.config' % V170604_16_PREFIX,
-                 '%s/proguardsettings/YouTubeRelease_proguard.config' % THIRD_PARTY],
+      'pgconf': ['%s_proguard.config' % V170604_16_PREFIX],
     },
     'proguarded' : {
       'inputs': ['%s_proguard.jar' % V170604_16_PREFIX],