Removing some UKM history aggregation in order to save resources.

Change-Id: Iba711bbf8384847bb14064604399c0748681ddf7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2288197Reviewed-by: Robert Kaplow <rkaplow@chromium.org>
Commit-Queue: Annie Sullivan <sullivan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#786427}

tools/metrics/ukm/ukm.xml

@@ -5042,11 +5042,8 @@ be describing additional metrics about the same event.
     </summary>
     <aggregation>
       <history>
-        <index fields="profile.country"/>
-        <index fields="profile.country,profile.system_ram"/>
         <index fields="profile.is_dominant_version"/>
         <index fields="profile.is_latest_version"/>
-        <index fields="profile.system_ram"/>
         <statistics>
           <quantiles type="std-percentiles"/>
         </statistics>
@@ -5060,11 +5057,8 @@ be describing additional metrics about the same event.
     </summary>
     <aggregation>
       <history>
-        <index fields="profile.country"/>
-        <index fields="profile.country,profile.system_ram"/>
         <index fields="profile.is_dominant_version"/>
         <index fields="profile.is_latest_version"/>
-        <index fields="profile.system_ram"/>
         <statistics>
           <quantiles type="std-percentiles"/>
         </statistics>
@@ -7794,8 +7788,6 @@ be describing additional metrics about the same event.
     <aggregation>
       <history>
         <index fields="profile.country"/>
-        <index fields="profile.country,profile.system_ram"/>
-        <index fields="profile.system_ram"/>
         <statistics>
           <quantiles type="std-percentiles"/>
         </statistics>
@@ -8274,7 +8266,6 @@ be describing additional metrics about the same event.
     </summary>
     <aggregation>
       <history>
-        <index fields="profile.country"/>
         <statistics>
           <quantiles type="std-percentiles"/>
         </statistics>
@@ -8327,11 +8318,6 @@ be describing additional metrics about the same event.
     </summary>
     <aggregation>
       <history>
-        <index fields="profile.country"/>
-        <index fields="profile.country,profile.system_ram"/>
-        <index fields="profile.is_dominant_version"/>
-        <index fields="profile.is_latest_version"/>
-        <index fields="profile.system_ram"/>
         <statistics>
           <quantiles type="std-percentiles"/>
         </statistics>
@@ -8346,11 +8332,6 @@ be describing additional metrics about the same event.
     </summary>
     <aggregation>
       <history>
-        <index fields="profile.country"/>
-        <index fields="profile.country,profile.system_ram"/>
-        <index fields="profile.is_dominant_version"/>
-        <index fields="profile.is_latest_version"/>
-        <index fields="profile.system_ram"/>
         <statistics>
           <quantiles type="std-percentiles"/>
         </statistics>
@@ -8365,11 +8346,6 @@ be describing additional metrics about the same event.
     </summary>
     <aggregation>
       <history>
-        <index fields="profile.country"/>
-        <index fields="profile.country,profile.system_ram"/>
-        <index fields="profile.is_dominant_version"/>
-        <index fields="profile.is_latest_version"/>
-        <index fields="profile.system_ram"/>
         <statistics>
           <quantiles type="std-percentiles"/>
         </statistics>
@@ -8773,7 +8749,6 @@ be describing additional metrics about the same event.
     </summary>
     <aggregation>
       <history>
-        <index fields="profile.country"/>
         <statistics>
           <quantiles type="std-percentiles"/>
         </statistics>