Add float support for set and get in CameraParameters.

bug:2375989
bug:2375987
diff --git a/libs/ui/CameraParameters.cpp b/libs/ui/CameraParameters.cpp
index 495e164..c4958a0 100644
--- a/libs/ui/CameraParameters.cpp
+++ b/libs/ui/CameraParameters.cpp
@@ -209,6 +209,13 @@
     set(key, str);
 }
 
+void CameraParameters::setFloat(const char *key, float value)
+{
+    char str[16];  // 14 should be enough. We overestimate to be safe.
+    snprintf(str, sizeof(str), "%g", value);
+    set(key, str);
+}
+
 const char *CameraParameters::get(const char *key) const
 {
     String8 v = mMap.valueFor(String8(key));
@@ -225,6 +232,13 @@
     return strtol(v, 0, 0);
 }
 
+float CameraParameters::getFloat(const char *key) const
+{
+    const char *v = get(key);
+    if (v == 0) return -1;
+    return strtof(v, 0);
+}
+
 static int parse_size(const char *str, int &width, int &height)
 {
     // Find the width.