samples: peripheral_gatt_dm: Increase Max Attribute count

Increase max attribute count due to Telephony and Media
service attribute count.
This fix allows the sample to be tested with nRF Connect
mobile application.

Jira: NCSDK-34680

Signed-off-by: Dominik Chat <dominik.chat@nordicsemi.no>

Author: dchat-nordic

samples/bluetooth/peripheral_gatt_dm/prj.conf

@@ -13,6 +13,7 @@ CONFIG_BT_GATT_CLIENT=y
 CONFIG_BT_GATT_DM=y
 CONFIG_HEAP_MEM_POOL_SIZE=1024
 CONFIG_BT_GATT_DM_DATA_PRINT=y
+CONFIG_BT_GATT_DM_MAX_ATTRS=40
 
 # Needed to print UUID.
 CONFIG_LOG=y