Restore agent MASTER_MEMORY default to 16GiB

The default MASTER_MEMORY was changed in some agent scenarios in order
to work around a problem in OKD where FCOS would use only 20% of RAM for
the ephemeral storage instead of 50%. Other scenarios were later changed
to match when tests started failing in 4.19 due to OCPBUGS-62790.

Return the defaults to the minimum values validated by assisted-service
in ABI, so that any future regressions like OCPBUGS-62790 are caught
immediately.

Author: zaneb

common.sh

@@ -472,28 +472,28 @@ if [[ ! -z ${AGENT_E2E_TEST_SCENARIO} ]]; then
           export NUM_MASTERS=5
           export MASTER_VCPU=${MASTER_VCPU:-4}
           export MASTER_DISK=${MASTER_DISK:-100}
-          export MASTER_MEMORY=${MASTER_MEMORY:-24576}
+          export MASTER_MEMORY=${MASTER_MEMORY:-16384}
           export NUM_WORKERS=0
           ;;
       "4CONTROL" )
           export NUM_MASTERS=4
           export MASTER_VCPU=${MASTER_VCPU:-4}
           export MASTER_DISK=${MASTER_DISK:-100}
-          export MASTER_MEMORY=${MASTER_MEMORY:-24576}
+          export MASTER_MEMORY=${MASTER_MEMORY:-16384}
           export NUM_WORKERS=0
           ;;
       "COMPACT" )
           export NUM_MASTERS=3
           export MASTER_VCPU=${MASTER_VCPU:-4}
           export MASTER_DISK=${MASTER_DISK:-100}
-          export MASTER_MEMORY=${MASTER_MEMORY:-32768}
+          export MASTER_MEMORY=${MASTER_MEMORY:-16384}
           export NUM_WORKERS=0
           ;;
       "TNA" )
           export NUM_MASTERS=2
           export MASTER_VCPU=${MASTER_VCPU:-8}
           export MASTER_DISK=${MASTER_DISK:-100}
-          export MASTER_MEMORY=${MASTER_MEMORY:-32768}
+          export MASTER_MEMORY=${MASTER_MEMORY:-16384}
           export NUM_ARBITERS=1
           export ARBITER_VCPU=${ARBITER_VCPU:-2}
           export ARBITER_MEMORY=${ARBITER_MEMORY:-8192}
@@ -505,7 +505,7 @@ if [[ ! -z ${AGENT_E2E_TEST_SCENARIO} ]]; then
           export NUM_MASTERS=2
           export MASTER_VCPU=${MASTER_VCPU:-8}
           export MASTER_DISK=${MASTER_DISK:-100}
-          export MASTER_MEMORY=${MASTER_MEMORY:-32768}
+          export MASTER_MEMORY=${MASTER_MEMORY:-16384}
           export NUM_WORKERS=${NUM_WORKERS:-0}
           export WORKER_DISK=${WORKER_DISK:-100}
           export ENABLE_TWO_NODE_FENCING="true"
@@ -514,7 +514,7 @@ if [[ ! -z ${AGENT_E2E_TEST_SCENARIO} ]]; then
           export NUM_MASTERS=3
           export MASTER_VCPU=${MASTER_VCPU:-4}
           export MASTER_DISK=${MASTER_DISK:-100}
-          export MASTER_MEMORY=${MASTER_MEMORY:-32768}
+          export MASTER_MEMORY=${MASTER_MEMORY:-16384}
           export NUM_WORKERS=2
           export WORKER_VCPU=${WORKER_VCPU:-4}
           export WORKER_DISK=${WORKER_DISK:-100}
@@ -524,7 +524,7 @@ if [[ ! -z ${AGENT_E2E_TEST_SCENARIO} ]]; then
           export NUM_MASTERS=1
           export MASTER_VCPU=${MASTER_VCPU:-8}
           export MASTER_DISK=${MASTER_DISK:-100}
-          export MASTER_MEMORY=${MASTER_MEMORY:-32768}
+          export MASTER_MEMORY=${MASTER_MEMORY:-16384}
           export NUM_WORKERS=0
           export NETWORK_TYPE="OVNKubernetes"
           export AGENT_PLATFORM_TYPE="${AGENT_PLATFORM_TYPE:-"none"}"
@@ -541,7 +541,7 @@ if [[ ! -z ${AGENT_E2E_TEST_SCENARIO} ]]; then
           export NUM_MASTERS=1
           export MASTER_VCPU=${MASTER_VCPU:-4}
           export MASTER_DISK=${MASTER_DISK:-100}
-          export MASTER_MEMORY=${MASTER_MEMORY:-32768}
+          export MASTER_MEMORY=${MASTER_MEMORY:-16384}
           export NUM_WORKERS=0
           export NETWORK_TYPE="OVNKubernetes"
           export AGENT_PLATFORM_TYPE="${AGENT_PLATFORM_TYPE:-"none"}"
@@ -560,6 +560,9 @@ if [[ ! -z ${AGENT_E2E_TEST_SCENARIO} ]]; then
     if ((MASTER_VCPU < 10)); then
       export MASTER_VCPU=10
     fi
+    if ((MASTER_MEMORY < 17920)); then
+      export MASTER_MEMORY=17920
+    fi
     if [ "${SCENARIO}" == "SNO" ]; then
        if ((MASTER_VCPU < 16)); then
         export MASTER_VCPU=16