Fix HdrCapabilities flattening

Modify vector reserve() to resize() to allocate and initialize the
updated vector

Bug: 64309771
Test: n/a
Change-Id: I76fd088493327b00cca39ef67e2362e4c79314be
diff --git a/libs/ui/HdrCapabilities.cpp b/libs/ui/HdrCapabilities.cpp
index 39adc5e..755e60c 100644
--- a/libs/ui/HdrCapabilities.cpp
+++ b/libs/ui/HdrCapabilities.cpp
@@ -76,7 +76,7 @@
     mMaxAverageLuminance = reinterpret_cast<float const&>(buf[1]);
     mMinLuminance        = reinterpret_cast<float const&>(buf[2]);
     if (itemCount) {
-        mSupportedHdrTypes.reserve(itemCount);
+        mSupportedHdrTypes.resize(itemCount);
         for (size_t i = 0; i < itemCount; ++i) {
             mSupportedHdrTypes[i] = buf[4 + i];
         }