Bump version to 6.0.15

Bump version to 6.0.15 for next release.

Author: martincostello

eng/Versions.props

@@ -3,7 +3,7 @@
   <PropertyGroup>
     <MajorVersion>6</MajorVersion>
     <MinorVersion>0</MinorVersion>
-    <PatchVersion>14</PatchVersion>
+    <PatchVersion>15</PatchVersion>
     <VersionPrefix>$(MajorVersion).$(MinorVersion).$(PatchVersion)</VersionPrefix>
     <PackageValidationBaselineVersion Condition="'$(PackageValidationBaselineVersion)' == ''">6.0.0</PackageValidationBaselineVersion>
     <PreReleaseVersionLabel>preview</PreReleaseVersionLabel>