Robustify logging of analytics about PackageInstaller.

This CL switches from the type-unsafe EventLog.writeEvent method to
the strictly-typed EventLogTags.writeInstallPackageAttempt. This
method is generated from the definition of this event in EventLogTags.logtags
and thus offers compile-time type checking.

Bug: 10605940

Change-Id: I62895b60fe4c01d4314eba564476e0f1ed7ad78b