Camera2: Change policy for calculating previewFpsRange from previewFps

Bug: 7259959
Change-Id: I759a559d7115201264f88db1f23edc2d6aef6c43
diff --git a/services/camera/libcameraservice/camera2/Parameters.h b/services/camera/libcameraservice/camera2/Parameters.h
index 53ddf99..cb9738b 100644
--- a/services/camera/libcameraservice/camera2/Parameters.h
+++ b/services/camera/libcameraservice/camera2/Parameters.h
@@ -267,6 +267,14 @@
     int arrayYToNormalized(int height) const;
     int normalizedXToArray(int x) const;
     int normalizedYToArray(int y) const;
+
+    struct Range {
+        int min;
+        int max;
+    };
+
+    int32_t fpsFromRange(int32_t min, int32_t max) const;
+
 };
 
 // This class encapsulates the Parameters class so that it can only be accessed