Revert "[CarPowerManager] Disable STR by default for everyone"

This reverts commit 3b08d0462e7a801fbe63977a8ec47333f616aa89.

Reason for revert: Breaking tests and somehow passed TH

Bug: 123542362
Change-Id: Ie92b6b8392be8fcd9bc9b6fdad2cd6f79acf6dd0
diff --git a/service/src/com/android/car/systeminterface/SystemStateInterface.java b/service/src/com/android/car/systeminterface/SystemStateInterface.java
index 4b4aaef..c963ac0 100644
--- a/service/src/com/android/car/systeminterface/SystemStateInterface.java
+++ b/service/src/com/android/car/systeminterface/SystemStateInterface.java
@@ -58,8 +58,7 @@
 
     default boolean isSystemSupportingDeepSleep() {
         //TODO should return by checking some kernel suspend control sysfs, bug: 32061842
-        //TODO should be enabled for cars that support STR. b: 121342851
-        return false;
+        return true;
     }
 
     default List<ProcessInfo> getRunningProcesses() {