Add "do not kill" install option

Passing the "--dont-kill" argument to pm install-create can be used to
install a feature split without killing the contianing application.
Use with caution.

Bug: 27780548
Change-Id: I743ac4f640c9c4251d1b3bc70ddf428bd79e07bf

cmds/pm/src/com/android/commands/pm/Pm.java

@@ -464,6 +464,9 @@ public final class Pm {
                 case "-g":
                     sessionParams.installFlags |= PackageManager.INSTALL_GRANT_RUNTIME_PERMISSIONS;
                     break;
+                case "--dont-kill":
+                    sessionParams.installFlags |= PackageManager.INSTALL_DONT_KILL_APP;
+                    break;
                 case "--originating-uri":
                     sessionParams.originatingUri = Uri.parse(nextOptionData());
                     break;