Add fixed read only flag to enable jerk prediction pruning

For now this flag will simply allow all motion predictions (no-op).

Test: atest libinput_tests
Bug: 266747654
Change-Id: If54b924223255c068fff26f8b6f21cdd31799aea
diff --git a/libs/input/input_flags.aconfig b/libs/input/input_flags.aconfig
index b48b0fb..e041c51 100644
--- a/libs/input/input_flags.aconfig
+++ b/libs/input/input_flags.aconfig
@@ -128,3 +128,12 @@
   description: "Enable fling scrolling to be stopped by putting a finger on the touchpad again"
   bug: "281106755"
 }
+
+flag {
+  name: "enable_prediction_pruning_via_jerk_thresholding"
+  namespace: "input"
+  description: "Enable prediction pruning based on jerk thresholds."
+  bug: "266747654"
+  is_fixed_read_only: true
+
+}