Add sendHint method to the PowerHintSession API for load changes

Add a new sendHint(SessionHint hint) method to the PowerHintSession to
allow clients to inform the session about upcoming changes in load ahead
of time.

Bug: b/243973548
Test: atest VtsHalPowerTargetTest
Change-Id: I0a8af42d3b0ccd3bbb72287a9b91ffb13fccaf9c
diff --git a/power/aidl/vts/Android.bp b/power/aidl/vts/Android.bp
index ea398ac..d5cc2b6 100644
--- a/power/aidl/vts/Android.bp
+++ b/power/aidl/vts/Android.bp
@@ -32,7 +32,7 @@
         "libbinder_ndk",
     ],
     static_libs: [
-        "android.hardware.power-V3-ndk",
+        "android.hardware.power-V4-ndk",
     ],
     test_suites: [
         "vts",