Correct spherical harmonics comments (#1375)

libs/image/include/image/KtxBundle.h

@@ -106,7 +106,7 @@ public:
     /**
      * Parses the key="sh" metadata and returns 3 bands of data.
      *
-     * Assumes 9 bands for a total of 27 coefficients.
+     * Assumes 3 bands for a total of 9 RGB coefficients.
      * Returns true if successful.
      */
     bool getSphericalHarmonics(filament::math::float3* result);

libs/image/src/KtxBundle.cpp

@@ -292,7 +292,7 @@ bool KtxBundle::getSphericalHarmonics(filament::math::float3* result) {
         return false;
     }
     float* flat = &result->x;
-    // 9 bands of 3 coefficients
+    // 3 bands, 9 RGB coefficients for a total of 27 floats.
     for (int i = 0; i < 9 * 3; i++) {
         char* next;
         *flat++ = std::strtof(src, &next);