Fixing errors

Here's a list of errors and their solutions.

no member named 'reserved_size' in 'private_handle_t'

Error:

hardware/qcom-caf/sm8150/display/gralloc/gr_buf_mgr.cpp:108:43: error: no member named 'reserved_size' in 'private_handle_t'
  108 |   uint64_t reserved_region_size = handle->reserved_size;
      |                                   ~~~~~~  ^
hardware/qcom-caf/sm8150/display/gralloc/gr_buf_mgr.cpp:127:45: error: no member named 'reserved_size' in 'private_handle_t'
  127 |     uint64_t reserved_region_size = handle->reserved_size;
      |                                     ~~~~~~  ^
hardware/qcom-caf/sm8150/display/gralloc/gr_buf_mgr.cpp:760:41: error: no member named 'reserved_size' in 'private_handle_t'
  760 |   auto meta_size = getMetaDataSize(hnd->reserved_size);
      |                                    ~~~  ^
hardware/qcom-caf/sm8150/display/gralloc/gr_buf_mgr.cpp:802:34: error: no member named 'reserved_size' in 'private_handle_t'
  802 |     buffer->reserved_size = hnd->reserved_size;
      |                             ~~~  ^
hardware/qcom-caf/sm8150/display/gralloc/gr_buf_mgr.cpp:1092:8: error: no member named 'reserved_size' in 'private_handle_t'
 1092 |   hnd->reserved_size = static_cast<unsigned int>(descriptor.GetReservedSize());
      |   ~~~  ^

Solution:

Set TARGET_GRALLOC_HANDLE_HAS_RESERVED_SIZE := true in BoardConfig

Related:

https://git.halogenos.org/halogenOS/android_product_halogenOS/-/commit/b5da4d50707005bae4e1ffbf7e725c69558bd06c