ci(custom-d1): add missing row_count option in the "prepare write" step

Without this option the default value '1000000' was used.
And this default value is much smaller than the desired value which was
set only with the "-d" key.

So, explicitly defined "row_count" option in addition to the "-d" one
with the same values just to write expected amount of data once.

test-cases/longevity/longevity-gce-custom-d1-workload1-hybrid-raid.yaml

@@ -9,11 +9,13 @@ prepare_write_cmd:
   - >-
     latte run --tag latte --duration 82286400 --request-timeout 60 --retry-interval '2s,10s'
     --threads 30 --connections 3 --concurrency 180 --rate 17000 --sampling 5s -P offset=0
-    --function load scylla-qa-internal/custom_d1/workload1/latte/custom_d1_workload1.rn
+    --function load -P row_count=82286400
+    scylla-qa-internal/custom_d1/workload1/latte/custom_d1_workload1.rn
   - >-
     latte run --tag latte --duration 82286400 --request-timeout 60 --retry-interval '2s,10s'
     --threads 30 --connections 3 --concurrency 180 --rate 17000 --sampling 5s -P offset=82286400
-    --function load scylla-qa-internal/custom_d1/workload1/latte/custom_d1_workload1.rn
+    --function load -P row_count=82286400
+    scylla-qa-internal/custom_d1/workload1/latte/custom_d1_workload1.rn
 stress_cmd:
   # NOTE: 'latte' tag will be used by the log collector code.
   # 01) T4F10 -> -r 51.5k (~1/2 from 103k) - part1

test-cases/longevity/longevity-gce-custom-d1-workload2-hybrid-raid.yaml

@@ -10,45 +10,45 @@ prepare_write_cmd:
   - >-
     latte run --tag latte --duration 75100100 --request-timeout 60 --retry-interval '2s,10s'
     --sampling 5s --threads 30 --connections 3 --concurrency 180 --rate 19000 -P offset=0
-    --function custom -P codes="\"T2F1,T14F1\""
+    --function custom -P codes="\"T2F1,T14F1\"" -P row_count=75100100
     scylla-qa-internal/custom_d1/workload2/latte/custom_d1_workload2.rn
   - >-
     latte run --tag latte --duration 75100100 --request-timeout 60 --retry-interval '2s,10s'
     --sampling 5s --threads 30 --connections 3 --concurrency 180 --rate 19000 -P offset=75100100
-    --function custom -P codes="\"T2F1,T14F1\""
+    --function custom -P codes="\"T2F1,T14F1\"" -P row_count=75100100
     scylla-qa-internal/custom_d1/workload2/latte/custom_d1_workload2.rn
 
   - >-
     latte run --tag latte --duration 35100100 --request-timeout 60 --retry-interval '2s,10s'
     --sampling 5s --threads 30 --connections 3 --concurrency 180 --rate 8900 -P offset=0
-    --function custom -P codes="\"T13F1\""
+    --function custom -P codes="\"T13F1\"" -P row_count=35100100
     scylla-qa-internal/custom_d1/workload2/latte/custom_d1_workload2.rn
   - >-
     latte run --tag latte --duration 35100100 --request-timeout 60 --retry-interval '2s,10s'
     --sampling 5s --threads 30 --connections 3 --concurrency 180 --rate 8900 -P offset=35100100
-    --function custom -P codes="\"T13F1\""
+    --function custom -P codes="\"T13F1\"" -P row_count=35100100
     scylla-qa-internal/custom_d1/workload2/latte/custom_d1_workload2.rn
 
   - >-
     latte run --tag latte --duration 25100100 --request-timeout 60 --retry-interval '2s,10s'
     --sampling 5s --threads 30 --connections 3 --concurrency 180 --rate 6350 -P offset=0
-    --function custom -P codes="\"T1F1,T3F1,T6F1,T9F1\""
+    --function custom -P codes="\"T1F1,T3F1,T6F1,T9F1\"" -P row_count=25100100
     scylla-qa-internal/custom_d1/workload2/latte/custom_d1_workload2.rn
   - >-
     latte run --tag latte --duration 25100100 --request-timeout 60 --retry-interval '2s,10s'
     --sampling 5s --threads 30 --connections 3 --concurrency 180 --rate 6350 -P offset=25100100
-    --function custom -P codes="\"T1F1,T3F1,T6F1,T9F1\""
+    --function custom -P codes="\"T1F1,T3F1,T6F1,T9F1\"" -P row_count=25100100
     scylla-qa-internal/custom_d1/workload2/latte/custom_d1_workload2.rn
 
   - >-
     latte run --tag latte --duration 5100100 --request-timeout 60 --retry-interval '2s,10s'
     --sampling 5s --threads 30 --connections 3 --concurrency 180 --rate 1280 -P offset=0
-    --function custom -P codes="\"T4F1,T5F1,T7F1\""
+    --function custom -P codes="\"T4F1,T5F1,T7F1\"" -P row_count=5100100
     scylla-qa-internal/custom_d1/workload2/latte/custom_d1_workload2.rn
   - >-
     latte run --tag latte --duration 5100100 --request-timeout 60 --retry-interval '2s,10s'
     --sampling 5s --threads 30 --connections 3 --concurrency 180 --rate 1280 -P offset=5100100
-    --function custom -P codes="\"T4F1,T5F1,T7F1\""
+    --function custom -P codes="\"T4F1,T5F1,T7F1\"" -P row_count=5100100
     scylla-qa-internal/custom_d1/workload2/latte/custom_d1_workload2.rn
 
 stress_cmd: